Changing the system clock with pexpect confuses pexpect!
See my code below.
I'm controlling a shell logged in as root with pexpect.
The class below has a method (startProc) which spawns a shell and
keeps it alive until told to destroy it (stopProc).
The other 2 methods in this class allow me to change the system clock
and to get the IP Address of this machine.
They all work fine except when I advance the system clock, and
then try to get the IP Address.
In that case, I get an exception because pexpect incorrectly thinks
the output it is getting from ifconfig is invalid. But it is not.
Pexpect is just confused. This doesn't happen when I move the clock
backwards. It only happens when I move the clock forward.
I believe what is going on is that internally pexpect uses the system
clock to keep track of when it receives data from spawned processes.
When I mess with the clock, that messes up the internal workings of
pexpect.
Any suggestions what I should do? I have numerous concurrent pexpect
processes running when I modify the clock. Is there anyway to prevent
them all from getting totally screwed up??
-
#!/usr/bin/env python
import pexpect, os, time, datetime, re
def reportPrint(string):
print string
def reportAssert(condition, string)
if condition == False:
print string
raise Exception
class rootManager:
rootProc = None
rootPrompt = ] %
myPrompt = ] %
def __init__(self):
pass
def startProc(self):
if self.rootProc != None:
reportPrint(\t\t- Root Process is already created)
else:
self.rootProc = pexpect.spawn ('/bin/tcsh',)
i = self.rootProc.expect([pexpect.TIMEOUT,
self.myPrompt,])
reportAssert(i != 0, Time-Out exiting)
reportPrint(\t\t- Sending su)
self.rootProc.sendline(su)
i = self.rootProc.expect([pexpect.TIMEOUT, Password: ,])
reportAssert(i != 0, Time-Out exiting)
reportPrint(\t\t- Sending Password)
self.rootProc.sendline(ROOT_PASSWORD)
i = self.rootProc.expect([pexpect.TIMEOUT,
self.rootPrompt,])
reportAssert(i != 0, Time-Out exiting)
reportPrint(\t\t- Root Process created)
def getIPAddr(self):
reportAssert(self.rootProc != None, No active Root Process!)
reportPrint(\t\t- Sending ifconfig -a)
self.rootProc.sendline(ifconfig -a)
i = self.rootProc.expect([pexpect.TIMEOUT, self.rootPrompt,])
reportAssert(i != 0, Time-Out exiting)
outputTxt = self.rootProc.before
ipList = [i for i in re.compile((?=inet )\d{1,3}\.\d{1,3}\.
\d{1,3}\.\d{1,3}).findall(outputTxt) if i != 127.0.0.1]
reportAssert(len(ipList) == 1, Cannot determine IP Address
from 'ifconfig -a': \n%s % outputTxt)
return ipList[0]
def changeClock(self, secondsDelta):
reportAssert(self.rootProc != None, No active Root Process!)
newTime = datetime.datetime.now() +
datetime.timedelta(seconds=secondsDelta)
dateStr = %02d%02d%02d%02d%s % (newTime.month, newTime.day,
newTime.hour, newTime.minute, str(newTime.year)[-2:])
reportPrint(\t\t- Sending 'date %s' command % dateStr)
self.rootProc.sendline(date %s % dateStr)
#Remember, by changing the clock, you are confusing pexpect's
timeout measurement!
# so ignore timeouts in this case
i = self.rootProc.expect([pexpect.TIMEOUT,
self.rootPrompt,],)
def stopProc(self):
if self.rootProc == None:
reportPrint(\t\t- Root Process is already destroyed)
else:
reportPrint(\t\t- Sending exit command)
rootProc.sendline(exit)
i = rootProc.expect([pexpect.TIMEOUT, self.myPrompt])
reportAssert(i != 0, Time-Out exiting)
reportPrint(\t\t- Sending exit command)
rootProc.sendline(exit)
i = rootProc.expect([pexpect.TIMEOUT, pexpect.EOF])
reportAssert(i != 0, Time-Out exiting)
self.rootProc.close()
self.rootProc = None
reportPrint(\t\t- Root Process Destroyed)
--
http://mail.python.org/mailman/listinfo/python-list
Re: Python Openings
Hi, I have just completed my B.tech this year and have above six months experience in OpenERP framework as a technical consultant.In these six months I have completed nearly 5 modules and acted as an active member.Now, my company is going under a financial crisis and so, I think I have to leave this job.But I want to continue my career in OpenERP or Python. Thanks and Regards! Vivek Poddar -- http://mail.python.org/mailman/listinfo/python-list
Re: Plot seems weird
On 12/26/2011 05:27 AM, Yigit Turgut wrote: On Dec 25, 7:06 pm, Rick Johnsonrantingrickjohn...@gmail.com wrote: On Dec 25, 9:33 am, Yigit Turguty.tur...@gmail.com wrote: Hi all, I have a text file as following; 0.2000470.00 0.2000530.16 0.2000590.00 0.2000650.08 0.2000720.00 0.2000780.16 And I am trying to plot it with ; filenames = sys.argv[1:] if len(filenames) == 0: filenames = [sys.stdin] for filename in filenames: t,y1 = numpy.genfromtxt(filename, unpack=True) pyplot.plot(t,y1) pyplot.show() But graph seems weird, not as it supposed to be. Any ideas ? Interesting. Of course weird leaves a LOT to be desired. On a scale of 1-10, how weird is the result? I apply a 1Khz test signal just to see if things run smoothly, but I see spikes at lower and higher ends (logic 0,1) where I should see a clean rectangle pwm signal. By the look of it I say weirdness is around 3/10. What are you expecting? Your data produces something that looks like the plot on the right of this screenshot (http://i44.tinypic.com/wwhlvp.jpg), I don't see anything weird with that; if you are expecting a square-wave-like plot (like on the left), then you should use a square-wave-like data, pyplot wouldn't magically transform a spiked-plot to squared-plot. Here's what I use to convert the data on right plot to data on left plot, I don't know much about numpy so it might be possible to do it more efficiently or numpy might even have something like it already. from itertools import izip_longest def to_square(t, y1): sq_data = [[], []] for x,y, xn in izip_longest(data[0], data[1], data[0][1:]): sq_data[0].append(x) sq_data[1].append(y) sq_data[0].append(xn) sq_data[1].append(y) return numpy.array(sq_data, dtype=float) -- http://mail.python.org/mailman/listinfo/python-list
Re: Backslash Escapes
On 12/26/2011 12:04 PM, Felipe O wrote: Hi all, Whenever I take any input (raw_input, of course!) or I read from a file, etc., any backslashes get escaped automatically. Python never escapes backslashes when reading from raw_input or files. Python only ever escapes backslashes when displaying data on the interactive shell since the interactive shell uses __repr__ by default. Is there any elegant way of parsing the backslashes as though they were written in a python string. The best I have so far right now goes like this: You shouldn't ever need to unless your file are backslash-escaped. -- http://mail.python.org/mailman/listinfo/python-list
Re: Test None for an object that does not implement ==
In article mailman.4097.1324877003.27778.python-l...@python.org, Devin Jeanpierre jeanpierr...@gmail.com wrote: Um -- if you don't want a and c being passed in, why put them in the function signature? He wants both or neither to be passed in. assert sum(foo is None for foo in [a, c]) % 2 == 0 -- http://mail.python.org/mailman/listinfo/python-list
Re: Changing the system clock with pexpect confuses pexpect!
In article 1f342621-0c96-447c-ad5d-f8c9dc777...@i6g2000vbe.googlegroups.com, Saqib Ali saqib.ali...@gmail.com wrote: I believe what is going on is that internally pexpect uses the system clock to keep track of when it receives data from spawned processes. When I mess with the clock, that messes up the internal workings of pexpect. Any suggestions what I should do? Yeah. Don't mess with the system clock. Seriously. There is pretty much no reason for anybody not to be running NTP these days. Every OS ships with it, and there's gazillions of open NTP servers to use as references. NTP will keep your system clock accurate to within a fraction of a second and avoid all the horrible problems such as the one you've discovered with pexpect when you reset your clock. -- http://mail.python.org/mailman/listinfo/python-list
Re: installing matplotlib in MacOs 10.6.8.
In article CAMW75Yv5f=PdcZqt-ti=iee7gxgfzqp8jxh485zjohd9l63...@mail.gmail.com, Alex Ter-Sarkissov ater1...@gmail.com wrote: hi everyone, I run python 2.7.2. in Eclipse (recently upgraded from 2.6). I have a problem with installing matplotlib (I found the version for python 2.7. MacOs 10.3, no later versions). If I run python in terminal using arch -i386 python, and then from matplotlib.pylab import * and similar stuff, everything works fine. If I run python in eclipse or just without arch -i386, I can import matplotlib as from matplotlib import * but actually nothing gets imported. If I do it in the same way as above, I get the message no matching architecture in universal wrapper which means there's conflict of versions or something like that. I tried reinstalling the interpreter and adding matplotlib to forced built-ins, but nothing helped. For some reason I didn't have this problem with numpy and tkinter. The message means almost certainly means that the Python you are using is a 64-bit/32-bit universal version. When you launch Python with -arch i386, you force the Python to run in 32-bit mode so it is compatible with the 32-bit-only version of matplotlib you've installed in it. When you launch Python by default, it is runnning in 64-bit mode so the 32-bit-only C extension modules in that version of matplotlib cannot be loaded. You might want to ask the matplotlib developers to make a 64-bit version available. In the mean time, you could try to configure Eclipse to invoke the python with `python2.7-32`, which is included with distributions like the python.org one to force Python to run in 32-bit mode on OS X. -- Ned Deily, n...@acm.org -- http://mail.python.org/mailman/listinfo/python-list
Re: Python education survey
On Dec 25, 9:27 pm, Chris Angelico ros...@gmail.com wrote: On Mon, Dec 26, 2011 at 4:44 AM, Rick Johnson [...] Conversely, why write an IDE into IDLE when perfectly-good IDEs already exist? I don't use IDLE for development per se; it's for interactive Python execution, but not editing of source files. I believe the answer is two fold: 1. Including an IDE like IDLE into the Python distro helps noobs to get started quickly without needing to traverse a gauntlet of unknown IDEs on their own. If later they find something that they feel is more appropriate; so be it. 2. (and most important to me... IDLE is written in Python using the Tkinter GUI (which ships with python also). Therefore, the source code for IDLE can be a GREAT teaching resource for how to write professional Tkinter applications. I KNOW THE CURRENT SOURCE SUCKS! However, we could change that. So, with those points being covered, i believe IDLE is very important to the Python community and could be useful to more people IF we clean it up a bit. It's really a great little IDE with even greater potential. If Guido would just say something (or at least some of the top Pythionistas (Hettinger i am looking at you!)) this community might work together to fix this problem. -- http://mail.python.org/mailman/listinfo/python-list
Re: Test None for an object that does not implement ==
GZ zyzhu2...@gmail.com writes: I run into a weird problem. I have a piece of code that looks like the following: f(, a=None, c=None): assert (a==None)==(c==None) There is only one 'None' - so use 'a is None' rather than 'a == None'. (In common lisp there is a particular language construct that allows you do determine whether an argument was passed in or was defaulted.) -- http://mail.python.org/mailman/listinfo/python-list
Re: Python education survey
On Mon, Dec 26, 2011 at 9:52 AM, Rick Johnson rantingrickjohn...@gmail.com wrote: On Dec 25, 9:27 pm, Chris Angelico ros...@gmail.com wrote: On Mon, Dec 26, 2011 at 4:44 AM, Rick Johnson [...] Conversely, why write an IDE into IDLE when perfectly-good IDEs already exist? I don't use IDLE for development per se; it's for interactive Python execution, but not editing of source files. I believe the answer is two fold: 1. Including an IDE like IDLE into the Python distro helps noobs to get started quickly without needing to traverse a gauntlet of unknown IDEs on their own. If later they find something that they feel is more appropriate; so be it. 2. (and most important to me... IDLE is written in Python using the Tkinter GUI (which ships with python also). Therefore, the source code for IDLE can be a GREAT teaching resource for how to write professional Tkinter applications. I KNOW THE CURRENT SOURCE SUCKS! However, we could change that. So, with those points being covered, i believe IDLE is very important to the Python community and could be useful to more people IF we clean it up a bit. It's really a great little IDE with even greater potential. If Guido would just say something (or at least some of the top Pythionistas (Hettinger i am looking at you!)) this community might work together to fix this problem. Not everyone who has Python installed wants to learn the language. I do think that a learning distro that has a lot of core tools pre-installed, and ships with some tutorials, would be a decent idea. Sort of like Enthought for new users :) I don't feel IDLE is worth salvaging though. Nathan -- http://mail.python.org/mailman/listinfo/python-list
Re: Plot seems weird
On Dec 26, 11:28 am, Lie Ryan lie.1...@gmail.com wrote: On 12/26/2011 05:27 AM, Yigit Turgut wrote: On Dec 25, 7:06 pm, Rick Johnsonrantingrickjohn...@gmail.com wrote: On Dec 25, 9:33 am, Yigit Turguty.tur...@gmail.com wrote: Hi all, I have a text file as following; 0.200047 0.00 0.200053 0.16 0.200059 0.00 0.200065 0.08 0.200072 0.00 0.200078 0.16 And I am trying to plot it with ; filenames = sys.argv[1:] if len(filenames) == 0: filenames = [sys.stdin] for filename in filenames: t,y1 = numpy.genfromtxt(filename, unpack=True) pyplot.plot(t,y1) pyplot.show() But graph seems weird, not as it supposed to be. Any ideas ? Interesting. Of course weird leaves a LOT to be desired. On a scale of 1-10, how weird is the result? I apply a 1Khz test signal just to see if things run smoothly, but I see spikes at lower and higher ends (logic 0,1) where I should see a clean rectangle pwm signal. By the look of it I say weirdness is around 3/10. What are you expecting? Your data produces something that looks like the plot on the right of this screenshot (http://i44.tinypic.com/wwhlvp.jpg), I don't see anything weird with that; if you are expecting a square-wave-like plot (like on the left), then you should use a square-wave-like data, pyplot wouldn't magically transform a spiked-plot to squared-plot. Here's what I use to convert the data on right plot to data on left plot, I don't know much about numpy so it might be possible to do it more efficiently or numpy might even have something like it already. from itertools import izip_longest def to_square(t, y1): sq_data = [[], []] for x,y, xn in izip_longest(data[0], data[1], data[0][1:]): sq_data[0].append(x) sq_data[1].append(y) sq_data[0].append(xn) sq_data[1].append(y) return numpy.array(sq_data, dtype=float) Thanks for the tip. I know that I feed a square wave signal and record this data. Thus I believe the situation can be related to sampling frequency. Couldn't get your code working, maybe because I import the data from file. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python education survey
On Dec 26, 10:11 am, Nathan Rice nathan.alexander.r...@gmail.com wrote: On Mon, Dec 26, 2011 at 9:52 AM, Rick Johnson rantingrickjohn...@gmail.com wrote: On Dec 25, 9:27 pm, Chris Angelico ros...@gmail.com wrote: On Mon, Dec 26, 2011 at 4:44 AM, Rick Johnson [...] Conversely, why write an IDE into IDLE when perfectly-good IDEs already exist? I don't use IDLE for development per se; it's for interactive Python execution, but not editing of source files. I believe the answer is two fold: 1. Including an IDE like IDLE into the Python distro helps noobs to get started quickly without needing to traverse a gauntlet of unknown IDEs on their own. If later they find something that they feel is more appropriate; so be it. 2. (and most important to me... IDLE is written in Python using the Tkinter GUI (which ships with python also). Therefore, the source code for IDLE can be a GREAT teaching resource for how to write professional Tkinter applications. I KNOW THE CURRENT SOURCE SUCKS! However, we could change that. So, with those points being covered, i believe IDLE is very important to the Python community and could be useful to more people IF we clean it up a bit. It's really a great little IDE with even greater potential. If Guido would just say something (or at least some of the top Pythionistas (Hettinger i am looking at you!)) this community might work together to fix this problem. Not everyone who has Python installed wants to learn the language. I'll admit you make a very valid point. But since they are not familiar with the language, what they don't know cannot hurt them. Although i do see a need to keep the core distro small. If we remove IDLE then we face the next big question... Should we remove Tkinter? I do think that a learning distro that has a lot of core tools pre-installed, and ships with some tutorials, would be a decent idea. Sort of like Enthought for new users :) This is the kind of inventiveness i have been looking for in this group. I think this is a great idea! I don't feel IDLE is worth salvaging though. Agreed. Not in it's current state anyway. -- http://mail.python.org/mailman/listinfo/python-list
Re: Test None for an object that does not implement ==
Devin Jeanpierre wrote: Um -- if you don't want a and c being passed in, why put them in the function signature? He wants both or neither to be passed in. Ah -- right. ~Ethan~ -- http://mail.python.org/mailman/listinfo/python-list
Re: Python education survey
On Mon, 26 Dec 2011 06:52:03 -0800, Rick Johnson wrote: If Guido would just say something (or at least some of the top Pythionistas (Hettinger i am looking at you!)) this community might work together to fix this problem. The sheer cluelessness displayed here about open source is painful. If Guido would just say something, this community would yawn. He's not the boss of us. Python development is an all-volunteer effort. The community works on projects that we find interesting, or that we need ourselves, not just because Guido says something about it -- and certainly not projects that you demand we work on. Instead of demanding that GvR order us to work on IDLE, put your money where your mouth is, Rick, and stop being a blow-hard. You've been nagging us about IDLE for long enough -- what is it now, two years? Three? I haven't been counting, but it feels like geological ages. Start a project to fix IDLE. There is plenty of free hosting on the Internet for open source projects, like GitHub and Google Code Hosting. Track some bugs. Plan some concrete enhancements. Write some actual code. Demonstrate actual effort, and you may attract others who care. Otherwise, you're wasting our time. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Is my IDLE problem caused by .idlerc? Permissions.
On 12/24/2011 11:35 AM, Dennis Lee Bieber wrote: On Sat, 24 Dec 2011 10:55:48 -0800, W. eWatson wolftra...@invalid.com wrote: Permissions as follows: SYSTEM: All. From Full control to write Account Unknown(S-1-5-21...): readexec, Read Wayne: (normal use) All. From Full control to write Admin: All. From Full control to write WMPNetwork: Read Comments? .idlerc permissions are slightly different for Account Unknown. Account Unknown refers to a user account that has been deleted (or, via some other system corruption, is no longer associated with a login name -- happened to me earlier this year: my user account name had been Wulfraed but the user account directory was under Dennis Lee Bieber... When the registry crashed it disconnected name Wulfraed from directory Dennis Lee Bieber... Lost a month of email once I got done creating a new user account where directory and name matched and restored from backup [I failed to back-up the old user directory before trying a remove/create user]). My suggestion would be, first, remove privileges for that remnant account where-ever found; check higher directory levels too, and try to propagate the privilege downwards. Second -- could the file itself be set for read-only on the simple properties? I just tested with Win7 -- setting the general read-only did not make any changes to any of the security tab users. Third, confirm the owner of the file is your current user account; if not,see if you can get take ownership option for the file to work. I wonder if removing the Account Unknown account might just do it. Not quite familiar with Owner, but I'll look around. I'll check the file for read only. -- http://mail.python.org/mailman/listinfo/python-list
Multithreading
I have a loop as following ; start = time.time() end = time.time() - start while(endN): data1 = self.chan1.getWaveform() end = time.time() - start timer.tick(10) #FPS screen.fill((255,255,255) if white else(0,0,0)) white = not white pygame.display.update() for i in range(self.size): end = time.time() - start f.write(%3.8f\t%f\n%(end,data1[i])) Roughly speaking, this loop displays something at 10 frames per second and writes data1 to a file with timestamps. At first loop data1 is grabbed but to grab the second value (second loop) it needs to wait for timer.tick to complete. When I change FPS value [timer.tick()], capturing period (time interval between loops) of data1 also changes. What I need is to run ; timer.tick(10) #FPS screen.fill((255,255,255) if white else(0,0,0)) white = not white pygame.display.update() for N seconds but this shouldn't effect the interval between loops thus I will be able to continuously grab data while displaying something at X fps. What would be an effective workaround for this situation ? -- http://mail.python.org/mailman/listinfo/python-list
Re: Plot seems weird
On 12/27/2011 04:08 AM, Yigit Turgut wrote: On Dec 26, 11:28 am, Lie Ryanlie.1...@gmail.com wrote: On 12/26/2011 05:27 AM, Yigit Turgut wrote: On Dec 25, 7:06 pm, Rick Johnsonrantingrickjohn...@gmail.comwrote: On Dec 25, 9:33 am, Yigit Turguty.tur...@gmail.comwrote: Hi all, I have a text file as following; 0.2000470.00 0.2000530.16 0.2000590.00 0.2000650.08 0.2000720.00 0.2000780.16 And I am trying to plot it with ; filenames = sys.argv[1:] if len(filenames) == 0: filenames = [sys.stdin] for filename in filenames: t,y1 = numpy.genfromtxt(filename, unpack=True) pyplot.plot(t,y1) pyplot.show() But graph seems weird, not as it supposed to be. Any ideas ? Interesting. Of course weird leaves a LOT to be desired. On a scale of 1-10, how weird is the result? I apply a 1Khz test signal just to see if things run smoothly, but I see spikes at lower and higher ends (logic 0,1) where I should see a clean rectangle pwm signal. By the look of it I say weirdness is around 3/10. What are you expecting? Your data produces something that looks like the plot on the right of this screenshot (http://i44.tinypic.com/wwhlvp.jpg), I don't see anything weird with that; if you are expecting a square-wave-like plot (like on the left), then you should use a square-wave-like data, pyplot wouldn't magically transform a spiked-plot to squared-plot. Here's what I use to convert the data on right plot to data on left plot, I don't know much about numpy so it might be possible to do it more efficiently or numpy might even have something like it already. from itertools import izip_longest def to_square(t, y1): sq_data = [[], []] for x,y, xn in izip_longest(data[0], data[1], data[0][1:]): sq_data[0].append(x) sq_data[1].append(y) sq_data[0].append(xn) sq_data[1].append(y) return numpy.array(sq_data, dtype=float) Thanks for the tip. I know that I feed a square wave signal and record this data. Thus I believe the situation can be related to sampling frequency. It is due to sampling frequency, but also because you cannot sample a square wave perfectly because square wave has infinite steepness at the transitions. Although if you know the exact timing of the transitions, it may be possible to reconstruct the transitions perfectly. Couldn't get your code working, maybe because I import the data from file. not your fault, I made a mistake when copy-pasteing the code, here's the fixed code: from itertools import izip_longest def to_square(data): sq_data = [[], []] for x,y, xn in izip_longest(data[0], data[1], data[0][1:]): sq_data[0].append(x) sq_data[1].append(y) sq_data[0].append(xn) sq_data[1].append(y) return numpy.array(sq_data, dtype=float) use it like this: t,y1 = to_square(numpy.genfromtxt(filename, unpack=True)) pyplot.plot(t,y1) pyplot.show() -- http://mail.python.org/mailman/listinfo/python-list
Re: Plot seems weird
On Dec 26, 8:58 pm, Lie Ryan lie.1...@gmail.com wrote: On 12/27/2011 04:08 AM, Yigit Turgut wrote: On Dec 26, 11:28 am, Lie Ryanlie.1...@gmail.com wrote: On 12/26/2011 05:27 AM, Yigit Turgut wrote: On Dec 25, 7:06 pm, Rick Johnsonrantingrickjohn...@gmail.com wrote: On Dec 25, 9:33 am, Yigit Turguty.tur...@gmail.com wrote: Hi all, I have a text file as following; 0.200047 0.00 0.200053 0.16 0.200059 0.00 0.200065 0.08 0.200072 0.00 0.200078 0.16 And I am trying to plot it with ; filenames = sys.argv[1:] if len(filenames) == 0: filenames = [sys.stdin] for filename in filenames: t,y1 = numpy.genfromtxt(filename, unpack=True) pyplot.plot(t,y1) pyplot.show() But graph seems weird, not as it supposed to be. Any ideas ? Interesting. Of course weird leaves a LOT to be desired. On a scale of 1-10, how weird is the result? I apply a 1Khz test signal just to see if things run smoothly, but I see spikes at lower and higher ends (logic 0,1) where I should see a clean rectangle pwm signal. By the look of it I say weirdness is around 3/10. What are you expecting? Your data produces something that looks like the plot on the right of this screenshot (http://i44.tinypic.com/wwhlvp.jpg), I don't see anything weird with that; if you are expecting a square-wave-like plot (like on the left), then you should use a square-wave-like data, pyplot wouldn't magically transform a spiked-plot to squared-plot. Here's what I use to convert the data on right plot to data on left plot, I don't know much about numpy so it might be possible to do it more efficiently or numpy might even have something like it already. from itertools import izip_longest def to_square(t, y1): sq_data = [[], []] for x,y, xn in izip_longest(data[0], data[1], data[0][1:]): sq_data[0].append(x) sq_data[1].append(y) sq_data[0].append(xn) sq_data[1].append(y) return numpy.array(sq_data, dtype=float) Thanks for the tip. I know that I feed a square wave signal and record this data. Thus I believe the situation can be related to sampling frequency. It is due to sampling frequency, but also because you cannot sample a square wave perfectly because square wave has infinite steepness at the transitions. Although if you know the exact timing of the transitions, it may be possible to reconstruct the transitions perfectly. Couldn't get your code working, maybe because I import the data from file. not your fault, I made a mistake when copy-pasteing the code, here's the fixed code: from itertools import izip_longest def to_square(data): sq_data = [[], []] for x,y, xn in izip_longest(data[0], data[1], data[0][1:]): sq_data[0].append(x) sq_data[1].append(y) sq_data[0].append(xn) sq_data[1].append(y) return numpy.array(sq_data, dtype=float) use it like this: t,y1 = to_square(numpy.genfromtxt(filename, unpack=True)) pyplot.plot(t,y1) pyplot.show() Significant improvement on the plot, pretty interesting. It runs ok but I need to know how?! (: -- http://mail.python.org/mailman/listinfo/python-list
Re: Is my IDLE problem caused by .idlerc? Permissions.
On 12/26/2011 10:16 AM, W. eWatson wrote: On 12/24/2011 11:35 AM, Dennis Lee Bieber wrote: On Sat, 24 Dec 2011 10:55:48 -0800, W. eWatson wolftra...@invalid.com wrote: Permissions as follows: SYSTEM: All. From Full control to write Account Unknown(S-1-5-21...): readexec, Read Wayne: (normal use) All. From Full control to write Admin: All. From Full control to write WMPNetwork: Read Comments? .idlerc permissions are slightly different for Account Unknown. Account Unknown refers to a user account that has been deleted (or, via some other system corruption, is no longer associated with a login name -- happened to me earlier this year: my user account name had been Wulfraed but the user account directory was under Dennis Lee Bieber... When the registry crashed it disconnected name Wulfraed from directory Dennis Lee Bieber... Lost a month of email once I got done creating a new user account where directory and name matched and restored from backup [I failed to back-up the old user directory before trying a remove/create user]). My suggestion would be, first, remove privileges for that remnant account where-ever found; check higher directory levels too, and try to propagate the privilege downwards. Second -- could the file itself be set for read-only on the simple properties? I just tested with Win7 -- setting the general read-only did not make any changes to any of the security tab users. Third, confirm the owner of the file is your current user account; if not,see if you can get take ownership option for the file to work. I wonder if removing the Account Unknown account might just do it. Not quite familiar with Owner, but I'll look around. I'll check the file for read only. Solved. Moving .idlerc to another folder for safe keeping, and letting IDLE create a new .idlerc folder did it. I don't have the slightest idea why that worked, but the troublesome file was dated 2/2010, probably from installing 2.5.2, and never touched again by attempts either to re-install 2.5.2 or move up to 2.7.2. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python education survey
On Tue, Dec 27, 2011 at 5:32 AM, Rick Johnson rantingrickjohn...@gmail.com wrote: Why has Guido not, at the very least, contacted me privately? He could remain anonymous. And how would you know if he did contact you anonymously? As to your demand that one of the top Pythionistas [sic] say something? I declare hereby that I am, in fact, a top Pythonista. [1] Rick, go fork Python onto Bitbucket. Call it Python 4000 if you like, or just Python with a better IDLE or whatever. Go! Shoo! Code! There. A top Pythonista has spoken. And if the above satisfy you not, I actually said it out loud too, just to be sure. That's how important you are to The Python Community (capital letters and all). ChrisA [1] Start here and follow the thread. I've done all of them. (Actually I probably haven't, and I haven't even read the whole thread, which just came up when I googled 'pythonista', but I defy you to prove me lying.) http://mail.python.org/pipermail/python-list/2003-June/207114.html -- http://mail.python.org/mailman/listinfo/python-list
Re: Multithreading
On Mon, Dec 26, 2011 at 11:31 AM, Yigit Turgut y.tur...@gmail.com wrote: I have a loop as following ; start = time.time() end = time.time() - start while(endN): data1 = self.chan1.getWaveform() end = time.time() - start timer.tick(10) #FPS screen.fill((255,255,255) if white else(0,0,0)) white = not white pygame.display.update() for i in range(self.size): end = time.time() - start f.write(%3.8f\t%f\n%(end,data1[i])) Roughly speaking, this loop displays something at 10 frames per second and writes data1 to a file with timestamps. At first loop data1 is grabbed but to grab the second value (second loop) it needs to wait for timer.tick to complete. When I change FPS value [timer.tick()], capturing period (time interval between loops) of data1 also changes. What I need is to run ; timer.tick(10) #FPS screen.fill((255,255,255) if white else(0,0,0)) white = not white pygame.display.update() for N seconds but this shouldn't effect the interval between loops thus I will be able to continuously grab data while displaying something at X fps. What would be an effective workaround for this situation ? You essentially have two completely independent loops that need to run simultaneously with different timings. Sounds like a good case for multiple threads (or processes if you prefer, but these aren: def write_data(self, f, N): start = time.time() while self.has_more_data(): data1 = self.chan1.getWaveform() time.sleep(N) for i in range(self.size): end = time.time() - start f.write(%3.8f\t%f\n % (end, data[i])) def write_data_with_display(self, f, N, X): thread = threading.Thread(target=self.write_data, args=(f, N)) thread.start() white = False while thread.is_alive(): timer.tick(X) screen.fill((255, 255, 255) if white else (0, 0, 0)) white = not white pygame.display.update() -- http://mail.python.org/mailman/listinfo/python-list
Re: Multithreading
On Mon, Dec 26, 2011 at 1:01 PM, Ian Kelly ian.g.ke...@gmail.com wrote: You essentially have two completely independent loops that need to run simultaneously with different timings. Sounds like a good case for multiple threads (or processes if you prefer, but these aren: I accidentally sent before I was finished. I was saying or processes if you prefer, but these aren't CPU-bound, so why complicate things? Cheers, Ian -- http://mail.python.org/mailman/listinfo/python-list
Re: Multithreading
On Dec 26, 10:03 pm, Ian Kelly ian.g.ke...@gmail.com wrote: On Mon, Dec 26, 2011 at 1:01 PM, Ian Kelly ian.g.ke...@gmail.com wrote: You essentially have two completely independent loops that need to run simultaneously with different timings. Sounds like a good case for multiple threads (or processes if you prefer, but these aren: I accidentally sent before I was finished. I was saying or processes if you prefer, but these aren't CPU-bound, so why complicate things? Cheers, Ian I had thought the same workaround but unfortunately loop is already under a def ; def writeWaveform(self, fo, header=''): data1 = numpy.zeros(self.size) screen = pygame.display.set_mode((0, 0), pygame.FULLSCREEN) timer = pygame.time.Clock() white = True fo.write(header) start = time.time() end = time.time() - start while(end10): data1 = self.chan1.getWaveform() end = time.time() - start timer.tick(10) #FPS screen.fill((255,255,255) if white else(0,0,0)) white = not white pygame.display.update() for i in range(self.size): end = time.time() - start f.write(%3.8f\t%f\n%(end,data1[i])) -- http://mail.python.org/mailman/listinfo/python-list
Re: Multithreading
On Mon, Dec 26, 2011 at 1:13 PM, Yigit Turgut y.tur...@gmail.com wrote: I had thought the same workaround but unfortunately loop is already under a def ; So nest the functions, or refactor it. Either way, that shouldn't be a significant obstacle. -- http://mail.python.org/mailman/listinfo/python-list
Re: Pythonification of the asterisk-based collection packing/unpacking syntax
On Dec 25, 5:15 pm, Steven D'Aprano steve
+comp.lang.pyt...@pearwood.info wrote:
On Sun, 25 Dec 2011 06:55:28 -0800, Eelco wrote:
Anyway, braces are used at
least an order of magnitude more than collection packing/ unpacking in
typical code.
That's a wild and unjustified claim. Here's a quick and dirty test, using
the standard library as an example of typical idiomatic code:
[steve@orac ~]$ cd /usr/lib/python2.6
[steve@orac python2.6]$ grep [*]args *.py | wc -l
270
[steve@orac python2.6]$ grep { *.py | wc -l
550
Doesn't look like a factor of 10 difference to me.
Now try it without changing the subject from round braces to
everything but round braces.
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Re: Pythonification of the asterisk-based collection packing/unpacking syntax
On Dec 25, 5:23 pm, Chris Angelico ros...@gmail.com wrote:
On Mon, Dec 26, 2011 at 2:38 AM, Eelco hoogendoorn.ee...@gmail.com wrote:
Until that time, im going
to ask you to take 'type constraint' by its literal meaning; a
coercion of the type of a symbol, rather than whatever particular
meaning it has acquired for you (it might help if you explained that).
Im not sure if it was you that brought that up, but let me reiterate
that I dont mean a 'type cast', which is a runtime concept. A 'type
constraint' is purely a linguistic construct that will be 'compiled
out')
The dictionary definition of constraint is a limitation or
restriction, and you're right that it can be compiled out. In fact,
that is probably the best definition. Assuming everything is written
correctly, you should be able to eliminate all constraints and the
code will still function correctly*; but having the constrains means
that certain illegal operations will throw errors.
Here's two examples of tuple unpacking, one with a type constraint,
the other without:
a, b = ('hello', [1,2,3] )
a, b::list = ('hello', [1,2,3] )
The constraint on the second line means that, if the second element is
not a list, the interpreter should throw an error. It does NOT mean to
completely change the meaning of the statement to _make_ the last
argument into a list. That is not the job of a constraint.
Thank you for providing clarification on what a 'type constraint'
means to you. That clears things up a bit.
What you are talking about goes by the name of a 'dynamic type CHECK';
some kind of syntactic sugar for something like
'assert(type(obj)==sometype)'. Like a 'type cast', this is also a
runtime concept. How you manage to confuse that with what I am talking
about, given that ive stated many times I am not talking about a
runtime construct but a compile-time construct, is quite beyond me.
(not to mention that ive quite explicitly stated what I mean by 'type
constraint' many times now).
By contrast, here is the first google hit for 'type constraint'.
http://msdn.microsoft.com/en-us/library/d5x73970.aspx
Note that this is a different application of the concept of a type
constraint, but nonetheless, the concept is as I stated it: a
constraint to the type of a symbol to modify its compile-time
semantics. To cite from its first paragraph:
...you can apply restrictions to the kinds of types ... by using a
type that is not allowed by a constraint, the result is a COMPILE-TIME
ERROR (emphasis mine)
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Re: Pythonification of the asterisk-based collection packing/unpacking syntax
On Tue, Dec 27, 2011 at 7:39 AM, Eelco hoogendoorn.ee...@gmail.com wrote:
Now try it without changing the subject from round braces to
everything but round braces.
Around here, the term braces means the curly ones - { and } - that
delimit blocks of code in C, and dictionaries/sets in Python.
Brackets may be what you're looking for, if you mean all of ()[]{}.
Or if you just mean (), they're called parentheses.
If your point is that parens are used more often than
packing/unpacking, that's almost certainly true, since function calls
(including method invocations) are so prevalent in pretty much any
code. But what does that prove?
ChrisA
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Re: Pythonification of the asterisk-based collection packing/unpacking syntax
On Tue, Dec 27, 2011 at 7:58 AM, Eelco hoogendoorn.ee...@gmail.com wrote: What you are talking about goes by the name of a 'dynamic type CHECK'; some kind of syntactic sugar for something like 'assert(type(obj)==sometype)'. Like a 'type cast', this is also a runtime concept... By contrast, here is the first google hit for 'type constraint'. http://msdn.microsoft.com/en-us/library/d5x73970.aspx ...you can apply restrictions to the kinds of types ... by using a type that is not allowed by a constraint, the result is a COMPILE-TIME ERROR (emphasis mine) A constraint can be applied at compile time or at run time. It'd be valid to apply them at edit time, if you so chose - your editor could refuse to save your file until you fix the problem. Doesn't mean a thing. Python, by its nature, cannot do compile-time type checking. Under no circumstances, however, does this justify the use of the term constraint to mean utterly different semantics of the same code. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: Pythonification of the asterisk-based collection packing/unpacking syntax
On Dec 25, 6:05 pm, Steven D'Aprano steve +comp.lang.pyt...@pearwood.info wrote: On Sun, 25 Dec 2011 07:38:17 -0800, Eelco wrote: On Dec 25, 2:12 pm, Steven D'Aprano steve +comp.lang.pyt...@pearwood.info wrote: On Sat, 24 Dec 2011 06:39:39 -0800, Eelco wrote: On Dec 20, 4:30 am, alex23 wuwe...@gmail.com wrote: On Dec 19, 8:15 pm, Eelco hoogendoorn.ee...@gmail.com wrote: What does that have to do with collection packing/unpacking? It's mocking your insistance that collection unpacking is a type constraint. This is really going to be the last time I waste any words on this: If only that were true, but after sending this post, you immediately followed up with FIVE more posts on this subject in less than half an hour. Did I waste any more words on collection packing and type constraints? No, I did not. (though I am about to, and am willing to do so for every question that seems genuinely aimed at engaging me on the matter) Did I intend to say that I was going to let a single troll shut down my entire topic? No, I did not. Ah, well whatever you *intended* wasn't clear from your comment. At least not clear to *me*. Always glad to help. Yes, indeed it would be abuse of language to call this a type constraint, since the fact that y is a list is indeed an outcome of whatever happens to pop out at the right hand side. One could redefine the identifier list to return any kind of object. So far, we agree on this. Good. How is 'head, *tail = sequence' or semantically entirely equivalently, 'head, tail::list = sequence' any different then? Of course after interpretation/compilation, what it boils down to is that we are constructing a list and binding it to the identifier tail, but that is not how it is formulated in python as a language I'm afraid it is. Here's the definition of assignment in Python 3:http://docs.python.org/py3k/reference/simple_stmts.html#assignment- statements Que? 'head, *tail = sequence' Is how one currently unpacks a head and tail in idiomatic python This is semantically equivalent to 'head = sequence[0]' 'tail = list(sequence[1:])' But these forms are linguistically different, in too many different ways to mention. We dont have something of the form 'tail = list_tail(sequence)'. I'm afraid we do. See the definition of assignment again. Que? My claim is that the two semantically identical formulations above do not have isomorphic linguistic form. As far as I can make sense of your words, you seem to be disputing this claim, but its a claim as much worth debating as that the sun rises in the east. Rather, we annotate the identifier 'tail' with an attribute that unquestionably destinates it to become a list*. It is no longer that 'tail' will just take anything that pops out of the expression on the right hand side; Of course it will. Python is a dynamically typed language. It doesn't suddenly develop static types to ensure that 'tail' becomes a list; 'tail' is bound to a list because that's what the assignment statement provides. How python accomplishes any of this under the hood is entirely immaterial. The form is that of a compile-time type constraint, regardless of whether the BDFL ever thought about it in these terms. rather, the semantics of what will go on at right hand side is coerced by the constraint placed on 'tail'. But it isn't a constraint placed on 'tail'. It is a consequence of the definition of assignment in Python 3. 'tail' becomes bound to a list because that is what the assignment statement is defined to do in that circumstance, not because the identifier (symbol) 'tail' is constrained to only accept lists. 'tail' may not even exist before hand, so talking about constraints on 'tail' is an abuse of language, AS YOU AGREED ABOVE. 'tail' is (re)declared on the spot as a brand-new identifier (type constraint included); whether it exists before has no significance whatsoever, since python allows rebinding of identifiers. *(I call that a 'type constraint', because that is what it literally is; No. It is literally a name binding of a dynamically typed, unconstrained name to an object which happens to be a list. Let me take a step back and reflect on the form of the argument we are having. I claim the object in front of us is a 'cube'. You deny this claim, by countering that it is 'just a particular configuration of atoms'. 'look at the definition!', you say; 'its just a list of coordinates, no mention of cubes whatsoever.'. 'Look at the definition of a cube', I counter. 'This particular list of coordinates happens to fit the definition, whether the BDFT intended to or not'. You are correct, in the sense that I do not disagree that it is a particular configuration of atoms. But if you had a better understanding of cubes, youd realize it meets the definition; the fact that people might not make a habit of pausing at this fact (there is generally speaking
Re: Pythonification of the asterisk-based collection packing/unpacking syntax
On Dec 26, 10:01 pm, Chris Angelico ros...@gmail.com wrote:
On Tue, Dec 27, 2011 at 7:39 AM, Eelco hoogendoorn.ee...@gmail.com wrote:
Now try it without changing the subject from round braces to
everything but round braces.
Around here, the term braces means the curly ones - { and } - that
delimit blocks of code in C, and dictionaries/sets in Python.
Brackets may be what you're looking for, if you mean all of ()[]{}.
Or if you just mean (), they're called parentheses.
If your point is that parens are used more often than
packing/unpacking, that's almost certainly true, since function calls
(including method invocations) are so prevalent in pretty much any
code. But what does that prove?
That proves the original point of contention: that the below* is
suboptimal language design, not because terseness always trumps
verbosity, but because commonly-used constructs (such as parenthesis
or round brackets or whatever you wish to call them) are more
deserving of the limited space in both the ascii table and your
reflexive memory, than uncommonly used ones.
*original mock code by steve:
class MyClass superclasslist A, B C:
def method argumentlist self, x, y:
t = tuple 1, 2 tuple 3, 4 endtuple endtuple
return group x + y endgroup * group x - y endgroup
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Re: Pythonification of the asterisk-based collection packing/unpacking syntax
On Dec 26, 10:05 pm, Chris Angelico ros...@gmail.com wrote: On Tue, Dec 27, 2011 at 7:58 AM, Eelco hoogendoorn.ee...@gmail.com wrote: What you are talking about goes by the name of a 'dynamic type CHECK'; some kind of syntactic sugar for something like 'assert(type(obj)==sometype)'. Like a 'type cast', this is also a runtime concept... By contrast, here is the first google hit for 'type constraint'. http://msdn.microsoft.com/en-us/library/d5x73970.aspx ...you can apply restrictions to the kinds of types ... by using a type that is not allowed by a constraint, the result is a COMPILE-TIME ERROR (emphasis mine) A constraint can be applied at compile time or at run time. It'd be valid to apply them at edit time, if you so chose - your editor could refuse to save your file until you fix the problem. Doesn't mean a thing. A constraint in the sense that I have explained many times now, can in no way, shape or form be applied at run time. Youd have better luck applying a consternation to a squirrel. Perhaps you meant 'type check' again? But then again, that makes no sense whatsoever at compile- time... Im starting to doubt if there is any sense to be found here at all. Anyway, ill take your further silence on the matter as a 'sorry I derailed your thread with my confusion of terminology' Python, by its nature, cannot do compile-time type checking. Python can do whatever its designers have put into it. In this case, that includes the emission of different code based on a (type) annotation at the point of declaration of an identifier (only in the particular circumstance of collection unpacking though, as far as I am aware). Under no circumstances, however, does this justify the use of the term constraint to mean utterly different semantics of the same code. Thank you for your theory on justice. Im sure its fascinating, but until you get around to actually explaining it, im going to have to be conservative and stick with the jargon in common use though, sorry. -- http://mail.python.org/mailman/listinfo/python-list
Re: Pythonification of the asterisk-based collection packing/unpacking syntax
On Tue, Dec 27, 2011 at 8:51 AM, Eelco hoogendoorn.ee...@gmail.com wrote: That proves the original point of contention: that [Steve's demo code] is suboptimal language design, not because terseness always trumps verbosity, but because commonly-used constructs (such as parenthesis or round brackets or whatever you wish to call them) are more deserving of the limited space in both the ascii table and your reflexive memory, than uncommonly used ones. In Magic: The Gathering RD, they have a term (the article reporting which I can't actually find at the moment) called spread complexity or fan complexity - the idea being that as you fan out a booster pack, you see a certain amount of complexity in front of you. The designers can afford to put more complex cards in as rares than they can as commons, because you see ten commons for every rare - so a common factors ten times as much as a rare in spread complexity. (Mark Rosewater, my apologies if I'm misremembering here!) The same applies here. When you cast your eye over a program, you're going to see certain syntactic elements a lot. Assignment, arithmetic, blocks of code (ie indent/dedent), and function calls are all extremely common; lambdas, the use of decorators, and exception handling are somewhat uncommon; and metaclasses, the writing of decorators, and reloading of modules are all quite rare. The elements that occur frequently should be: a) Readable and grokkable; b) Easily typed on a regular keyboard - no using ASCII character 126 to mean negation, tyvm! c) Make sense. Rarer elements (and I'm not talking about xenon and plutonium here) are allowed to have long names, obscure syntax, or even be shoved away in odd modules (the way module reloading is in Python 3). If 0.1% of your code is suddenly twice as large as it used to be, will you notice? But if a new syntax adds even 5% to the mindspace requirement of basic assignment, your code will majorly suffer. In summary: Terseness trumps verbosity primarily for common operations, and only when doing so does not violate rules a and c above. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Possible bug in string handling (with kludgy work-around)
This doesn't cause a crash, but rather incorrect results. self.wordList=[The, quick, brown, fox, carefully, jumps, over, the, lazy, dog, as, it, stealthily, wends, its, way, homewards, '\b.'] foriinrange (len (self.wordList) ): ifnot isinstance(self.wordList[i], str): self.wordList = elif self.wordList[i] != and self.wordList[i][0] == \b: print (0: wordList[, i, ] = \, self.wordList[i], \, sep = ) print (0a: wordList[, i, ][1] = \, self.wordList[i][1], \, sep = ) tmp=self.wordList[i][1] ## !! Kludge -- remove tmp to see the error self.wordList[i]=tmp + self.wordList[i][1:-1] ## !! Kludge -- remove tmp + to see the error print (1: wordList[, i, ] = \, self.wordList[i], \, sep = ) print(len(wordList[, i, ]) = , len(self.wordList[i]) ) -- Charles Hixson -- http://mail.python.org/mailman/listinfo/python-list
Re: Pythonification of the asterisk-based collection packing/unpacking syntax
On Tue, Dec 27, 2011 at 9:12 AM, Eelco hoogendoorn.ee...@gmail.com wrote: On Dec 26, 10:05 pm, Chris Angelico ros...@gmail.com wrote: A constraint can be applied at compile time or at run time. It'd be valid to apply them at edit time, if you so chose - your editor could refuse to save your file until you fix the problem. Doesn't mean a thing. A constraint in the sense that I have explained many times now, can in no way, shape or form be applied at run time. Youd have better luck applying a consternation to a squirrel. Perhaps you meant 'type check' again? But then again, that makes no sense whatsoever at compile- time... Im starting to doubt if there is any sense to be found here at all. A constraint failure causes an error at the time it's discovered. 1) Your editor pops up a message the instant you type something with such an error, and forces you to correct it before going on. 2) Your compiler refuses to produce byte-code for the module. 3) When the line of code is executed, an exception is thrown. All of these are valid ways of handling a constraint. Here is a Python example of a type constraint: def foo(arg): if not isinstance(arg,list): raise This won't work. If you call it with something that's not a list, you get an error. Call it with a list, and execution continues normally. That's a constraint. Of course, it might not be a _type_ constraint: def foo(arg): if arg5: raise This won't work either. # and yes, that's oddly truer in Python 3 (Aside: In Pike, I can actually put that into a type constraint (declare the argument to be int(5..) for instance). This, however, is not germane to the conversation.) Anyway, ill take your further silence on the matter as a 'sorry I derailed your thread with my confusion of terminology' Like Mary Poppins, I never apologize for derailing threads :) Python, by its nature, cannot do compile-time type checking. Python can do whatever its designers have put into it. In this case, that includes the emission of different code based on a (type) annotation at the point of declaration of an identifier (only in the particular circumstance of collection unpacking though, as far as I am aware). Of course, but how can Python, without a completely different structure, do compile-time checking of object types? Everything can be monkey-patched at run-time. Anything could be affected by any function call. It's impossible to say for certain, at compile time, what data type anything will have. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: Possible bug in string handling (with kludgy work-around)
On Tue, Dec 27, 2011 at 9:23 AM, Charles Hixson charleshi...@earthlink.net wrote: This doesn't cause a crash, but rather incorrect results. You may need to be a bit clearer. What line of code (or what expression)? What did you expect to see, and what did you see? From examining your code, I've come up with one most-likely scenario. In Python, indexing is zero-based and, in effect, indexes the boundaries between items rather than the items themselves. Referencing string[-1] actually means asking for the boundary between the second-last and last characters; using that as your end marker actually trims off the last character. What you may want is simply: self.wordList[i][1:] which means from character position 1 to the end of the string. Hope that helps! Chris Angelico -- http://mail.python.org/mailman/listinfo/python-list
Re: How to check for single character change in a string?
Roy Smith r...@panix.com wrote: In article roy-aaaeea.10571424122...@news.panix.com, Roy Smith r...@panix.com wrote: len([x for x in zip(s1, s2) if x[0] != x[1]]) Heh, Ian Kelly's version: sum(a == b for a, b in zip(str1, str2)) is cleaner than mine. Except that Ian's counts matches and the OP asked for non-matches, but that's an exercise for the reader :-) :-) I'm actually walking through a directory tree and checking that file characteristics don't change in a sequence of files. What I'm looking for is 'unusual' changes in file characteristics (they're image files with camera information and such in them) in a sequential list of files. Thus if file001, file002, file003, file004 have the same camera type I'm happy, but if file003 appears to have been taken with a different camera something is probably amiss. I realise there will be *two* character changes when going from file009 to file010 but I can cope with that. I can't just extract the sequence number because in some cases they have non-numeric names, etc. -- Chris Green -- http://mail.python.org/mailman/listinfo/python-list
Re: Possible bug in string handling (with kludgy work-around)
On Dec 26, 4:23 pm, Charles Hixson charleshi...@earthlink.net wrote: This doesn't cause a crash, but rather incorrect results. self.wordList = [The, quick, brown, fox, carefully, jumps, over, the, lazy, dog, as, it, stealthily, wends, its, way, homewards, '\b.'] for i in range (len (self.wordList) ): if not isinstance(self.wordList[i], str): self.wordList = elif self.wordList[i] != and self.wordList[i][0] == \b: print (0: wordList[, i, ] = \, self.wordList[i], \, sep = ) print (0a: wordList[, i, ][1] = \, self.wordList[i][1], \, sep = ) tmp = self.wordList[i][1] ## !! Kludge -- remove tmp to see the error self.wordList[i] = tmp + self.wordList[i][1:-1] ## !! Kludge -- remove tmp + to see the error print (1: wordList[, i, ] = \, self.wordList[i], \, sep = ) print (len(wordList[, i, ]) = , len(self.wordList[i]) ) -- Charles Hixson Handy rules for reporting bugs: 1. Always format code properly. 2. Always trim excess fat from code. 3. Always include relative dependencies (self.wordlist is only valid inside a class. In this case, change the code to a state that is NOT dependent on a class definition.) Most times after following these simple rules, you'll find egg on your face BEFORE someone else has a chance to see it and ridicule you. -- http://mail.python.org/mailman/listinfo/python-list
Re: Possible bug in string handling (with kludgy work-around)
On Tue, Dec 27, 2011 at 9:48 AM, Rick Johnson rantingrickjohn...@gmail.com wrote: Handy rules for reporting bugs: 1. Always format code properly. 2. Always trim excess fat from code. 3. Always include relative dependencies (self.wordlist is only valid inside a class. In this case, change the code to a state that is NOT dependent on a class definition.) Most times after following these simple rules, you'll find egg on your face BEFORE someone else has a chance to see it and ridicule you. 4. Don't take it personally when a known troll insults you. His advice, in this case, is valid; but don't feel that you're going to be ridiculed. We don't work that way on this list. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: Multithreading
On Dec 26, 10:01 pm, Ian Kelly ian.g.ke...@gmail.com wrote: On Mon, Dec 26, 2011 at 11:31 AM, Yigit Turgut y.tur...@gmail.com wrote: I have a loop as following ; start = time.time() end = time.time() - start while(endN): data1 = self.chan1.getWaveform() end = time.time() - start timer.tick(10) #FPS screen.fill((255,255,255) if white else(0,0,0)) white = not white pygame.display.update() for i in range(self.size): end = time.time() - start f.write(%3.8f\t%f\n%(end,data1[i])) Roughly speaking, this loop displays something at 10 frames per second and writes data1 to a file with timestamps. At first loop data1 is grabbed but to grab the second value (second loop) it needs to wait for timer.tick to complete. When I change FPS value [timer.tick()], capturing period (time interval between loops) of data1 also changes. What I need is to run ; timer.tick(10) #FPS screen.fill((255,255,255) if white else(0,0,0)) white = not white pygame.display.update() for N seconds but this shouldn't effect the interval between loops thus I will be able to continuously grab data while displaying something at X fps. What would be an effective workaround for this situation ? You essentially have two completely independent loops that need to run simultaneously with different timings. Sounds like a good case for multiple threads (or processes if you prefer, but these aren: def write_data(self, f, N): start = time.time() while self.has_more_data(): data1 = self.chan1.getWaveform() time.sleep(N) for i in range(self.size): end = time.time() - start f.write(%3.8f\t%f\n % (end, data[i])) Why is there N variable in write_data function ? N is related to timer.tick(N) which is related to display function ? time.sleep(N) will pause writing to file for specified amount of time which is exactly what I am trying to avoid. -- http://mail.python.org/mailman/listinfo/python-list
Regular expressions
Hi I am trying to change @HWI-ST115:568:B08LLABXX:1:1105:6465:151103 1:N: 0: to @HWI-ST115:568:B08LLABXX:1:1105:6465:151103/1. Can anyone help me with the regular expressions needed? Thanks in advance. Maurice -- http://mail.python.org/mailman/listinfo/python-list
installing matplotlib in MacOs 10.6.8.
thanks Ned, that's quite weird: if I run python2.7-32 in terminal, it works like you said, but when I add it as an interpreter in Eclipse, matplotlib.pyplot doesn't get imported for some reason. Even more strange, either way platform.architecture() reports 64-bit. What's wrong here? cheers, Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: installing matplotlib in MacOs 10.6.8.
thanks Ned, that's quite weird: if I run python2.7-32 in terminal, it works like you said, but when I add it as an interpreter in Eclipse, matplotlib.pyplot doesn't get imported for some reason. Even more strange, either way platform.architecture() reports 64-bit. What's wrong here? cheers, Alex 27 декабря 2011 г. 3:54 пользователь Ned Deily n...@acm.org написал: In article CAMW75Yv5f=PdcZqt-ti=iee7gxgfzqp8jxh485zjohd9l63...@mail.gmail.com, Alex Ter-Sarkissov ater1...@gmail.com wrote: hi everyone, I run python 2.7.2. in Eclipse (recently upgraded from 2.6). I have a problem with installing matplotlib (I found the version for python 2.7. MacOs 10.3, no later versions). If I run python in terminal using arch -i386 python, and then from matplotlib.pylab import * and similar stuff, everything works fine. If I run python in eclipse or just without arch -i386, I can import matplotlib as from matplotlib import * but actually nothing gets imported. If I do it in the same way as above, I get the message no matching architecture in universal wrapper which means there's conflict of versions or something like that. I tried reinstalling the interpreter and adding matplotlib to forced built-ins, but nothing helped. For some reason I didn't have this problem with numpy and tkinter. The message means almost certainly means that the Python you are using is a 64-bit/32-bit universal version. When you launch Python with -arch i386, you force the Python to run in 32-bit mode so it is compatible with the 32-bit-only version of matplotlib you've installed in it. When you launch Python by default, it is runnning in 64-bit mode so the 32-bit-only C extension modules in that version of matplotlib cannot be loaded. You might want to ask the matplotlib developers to make a 64-bit version available. In the mean time, you could try to configure Eclipse to invoke the python with `python2.7-32`, which is included with distributions like the python.org one to force Python to run in 32-bit mode on OS X. -- Ned Deily, n...@acm.org -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: Regular expressions
On Tue, Dec 27, 2011 at 10:45 AM, mauricel...@acm.org mauricel...@gmail.com wrote: Hi I am trying to change one string to another string. Can anyone help me with the regular expressions needed? A regular expression defines a string based on rules. Without seeing a lot more strings, we can't know what possibilities there are for each part of the string. You probably know your data better than we ever will, even eyeballing the entire set of strings; just write down, in order, what the pieces ought to be - for instance, the first token might be a literal @ sign, followed by three upper-case letters, then a hyphen, then any number of alphanumerics followed by a colon, etc. Once you have that, it's fairly straightforward to translate that into regex syntax. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: Regular expressions
In article
495b6fe6-704a-42fc-b10b-484218ad8...@b20g2000pro.googlegroups.com,
mauricel...@acm.org mauricel...@gmail.com wrote:
Hi
I am trying to change @HWI-ST115:568:B08LLABXX:1:1105:6465:151103 1:N:
0: to @HWI-ST115:568:B08LLABXX:1:1105:6465:151103/1.
Can anyone help me with the regular expressions needed?
Easy-peasy:
import re
input = @HWI-ST115:568:B08LLABXX:1:1105:6465:151103 1:N: 0:
output = @HWI-ST115:568:B08LLABXX:1:1105:6465:151103/1
pattern = re.compile(
r'@HWI-ST115:568:B08LLABXX:1:1105:6465:151103 1:N: 0:')
out = pattern.sub(
r'@HWI-ST115:568:B08LLABXX:1:1105:6465:151103/1',
input)
assert out == output
To be honest, I wouldn't do this with a regex. I'm not quite sure what
you're trying to do, but I'm guessing it's something like Get
everything after the first space in the string; keep just the integer
that's before the first ':' in that and turn the space into a slash.
In that case, I'd do something like:
head, tail = input.split(' ', 1)
number, _ = tail.split(':')
print %s/%s % (head, number)
--
http://mail.python.org/mailman/listinfo/python-list
Re: Regular expressions
On Tue, Dec 27, 2011 at 10:45 AM, mauricel...@acm.org mauricel...@gmail.com wrote: Hi I am trying to change one string to another string. Can anyone help me with the regular expressions needed? A regular expression defines a string based on rules. Without seeing a lot more strings, we can't know what possibilities there are for each part of the string. You probably know your data better than we ever will, even eyeballing the entire set of strings; just write down, in order, what the pieces ought to be - for instance, the first token might be a literal @ sign, followed by three upper-case letters, then a hyphen, then any number of alphanumerics followed by a colon, etc. Once you have that, it's fairly straightforward to translate that into regex syntax. ChrisA -- http://mail.python.org/mailman/listinfo/python-list The OP told me, off list, that my guess was true: Can we say that your string: 1) Contains 7 colon-delimited fields, followed by 2) whitespace, followed by 3) 3 colon-delimited fields (A, B, C), followed by 4) a colon? The transformation needed is that the whitespace is replaced by a slash, the A characters are taken as is, and the colons and fields following the A characters are eliminated? Doubtful that my guess was 100% accurate, but nevertheless: import re string1 = @HWI-ST115:568:B08LLABXX:1:1105:6465:151103 1:N:0: re.sub(r(\S+)\s+(\S+?):.+, \g1/\g2, string1) '@HWI-ST115:568:B08LLABXX:1:1105:6465:151103/1' -- http://mail.python.org/mailman/listinfo/python-list
Re: Regular expressions
On Dec 27, 8:00 am, Chris Angelico ros...@gmail.com wrote:
On Tue, Dec 27, 2011 at 10:45 AM, mauricel...@acm.org
mauricel...@gmail.com wrote:
Hi
I am trying to change one string to another string.
Can anyone help me with the regular expressions needed?
A regular expression defines a string based on rules. Without seeing a
lot more strings, we can't know what possibilities there are for each
part of the string. You probably know your data better than we ever
will, even eyeballing the entire set of strings; just write down, in
order, what the pieces ought to be - for instance, the first token
might be a literal @ sign, followed by three upper-case letters, then
a hyphen, then any number of alphanumerics followed by a colon, etc.
Once you have that, it's fairly straightforward to translate that into
regex syntax.
ChrisA
I've tried
re.sub('@\S\s[1-9]:[A-N]:[0-9]', '@\S\s', '@HWI-ST115:568:B08LLABXX:
1:1105:6465:151103 1:N:0:')
but it does not seems to work.
--
http://mail.python.org/mailman/listinfo/python-list
Re: Regular expressions
On Dec 27, 8:16 am, Jason Friedman ja...@powerpull.net wrote: On Tue, Dec 27, 2011 at 10:45 AM, mauricel...@acm.org mauricel...@gmail.com wrote: Hi I am trying to change one string to another string. Can anyone help me with the regular expressions needed? A regular expression defines a string based on rules. Without seeing a lot more strings, we can't know what possibilities there are for each part of the string. You probably know your data better than we ever will, even eyeballing the entire set of strings; just write down, in order, what the pieces ought to be - for instance, the first token might be a literal @ sign, followed by three upper-case letters, then a hyphen, then any number of alphanumerics followed by a colon, etc. Once you have that, it's fairly straightforward to translate that into regex syntax. ChrisA -- http://mail.python.org/mailman/listinfo/python-list The OP told me, off list, that my guess was true: Can we say that your string: 1) Contains 7 colon-delimited fields, followed by 2) whitespace, followed by 3) 3 colon-delimited fields (A, B, C), followed by 4) a colon? The transformation needed is that the whitespace is replaced by a slash, the A characters are taken as is, and the colons and fields following the A characters are eliminated? Doubtful that my guess was 100% accurate, but nevertheless: import re string1 = @HWI-ST115:568:B08LLABXX:1:1105:6465:151103 1:N:0: re.sub(r(\S+)\s+(\S+?):.+, \g1/\g2, string1) '@HWI-ST115:568:B08LLABXX:1:1105:6465:151103/1' Thanks a lot everyone. Can anyone suggest a good place to learn REs? ML -- http://mail.python.org/mailman/listinfo/python-list
Re: Pythonification of the asterisk-based collection packing/unpacking syntax
On Dec 26, 11:27 pm, Chris Angelico ros...@gmail.com wrote: On Tue, Dec 27, 2011 at 8:51 AM, Eelco hoogendoorn.ee...@gmail.com wrote: That proves the original point of contention: that [Steve's demo code] is suboptimal language design, not because terseness always trumps verbosity, but because commonly-used constructs (such as parenthesis or round brackets or whatever you wish to call them) are more deserving of the limited space in both the ascii table and your reflexive memory, than uncommonly used ones. In Magic: The Gathering RD, they have a term (the article reporting which I can't actually find at the moment) called spread complexity or fan complexity - the idea being that as you fan out a booster pack, you see a certain amount of complexity in front of you. The designers can afford to put more complex cards in as rares than they can as commons, because you see ten commons for every rare - so a common factors ten times as much as a rare in spread complexity. (Mark Rosewater, my apologies if I'm misremembering here!) The same applies here. When you cast your eye over a program, you're going to see certain syntactic elements a lot. Assignment, arithmetic, blocks of code (ie indent/dedent), and function calls are all extremely common; lambdas, the use of decorators, and exception handling are somewhat uncommon; and metaclasses, the writing of decorators, and reloading of modules are all quite rare. The elements that occur frequently should be: a) Readable and grokkable; b) Easily typed on a regular keyboard - no using ASCII character 126 to mean negation, tyvm! c) Make sense. Rarer elements (and I'm not talking about xenon and plutonium here) are allowed to have long names, obscure syntax, or even be shoved away in odd modules (the way module reloading is in Python 3). If 0.1% of your code is suddenly twice as large as it used to be, will you notice? But if a new syntax adds even 5% to the mindspace requirement of basic assignment, your code will majorly suffer. In summary: Terseness trumps verbosity primarily for common operations, and only when doing so does not violate rules a and c above. ChrisA Good to see there is something we agree upon completely. Not that I mean to say the question as to how verbose a syntax is appropriate for collection (un)packing is settled; one could reasonably argue they find tail::tuple too verbose. But parenthesis are not a terribly good example to compare to, since they are infact so much more used they are clearly in another category. *args and **kwargs are debateable in the appropriateness of their terseness (but I personally like to err on the side of verbosity), but extended collection unpacking, as in 'head,*tail=sequence', is quite a rare construct indeed, and here I very strongly feel a more explicit syntax is preferrable. That is, as a seasoned python 2 user, I wouldnt have been willing to gamble on what this does when id come across it for the first time in python 3. Could as well be a completely new use of the asterisk. But if collection packing/unpacking would be presented as a more general construct from the start, 'head,tail::tuple=sequence' would be hard to miss. -- http://mail.python.org/mailman/listinfo/python-list
Re: Pythonification of the asterisk-based collection packing/unpacking syntax
On Tue, Dec 27, 2011 at 10:44 AM, Eelco hoogendoorn.ee...@gmail.com wrote: extended collection unpacking, as in 'head,*tail=sequence', is quite a rare construct indeed, and here I very strongly feel a more explicit syntax is preferrable. You may be right, but... ... if collection packing/unpacking would be presented as a more general construct from the start, 'head,tail::tuple=sequence' would be hard to miss. ... it doesn't really justify a _change_. When a language is in its infancy and the only code written in it is on the designers' own computers, these sorts of debates can be tipped by relatively small differences - is it more readable, is it quick enough to type, etc. But once a language reaches a level of maturity, changes need to overwhelm the but it's a change hurdle - breaking existing code is majorly dangerous, and keeping two distinct ways of doing something means you get the worst of both worlds. We can argue till the cows come home as to which way would be better, _had Python started with it_. I don't think there's anything like enough difference to justify the breakage/duplication. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: Possible bug in string handling (with kludgy work-around)
On Mon, 26 Dec 2011 14:23:03 -0800, Charles Hixson wrote: This doesn't cause a crash, but rather incorrect results. Charles, your code is badly formatted and virtually unreadable. You have four spaces between some tokens, lines are too long to fit in an email or News post without word-wrapping. It is a mess of unidiomatic code filled with repeated indexing and unnecessary backslash escapes. You also don't tell us what result you expect, or what result you actually get. What is the intention of the code? What are you trying to do, and what happens instead? The code as given doesn't run -- what's self? Despite all these problems, I can see one obvious problem in your code: you test to see if self.wordList[i] is a string, and if not, you replace the *entire* wordList with the empty string. That is unlikely to do what you want, although I admit I'm guessing what you are trying to do (since you don't tell us). Some hints for you: (1) Python has two string delimiters, and ' and you should use them both. Instead of hard-to-read backslash escapes, just swap delimiters: print A string including a \ quote mark. # No! print 'A string including a quote mark.' # Yes, much easier to read. The only time you should backslash-escape a quotation mark is if you need to include both sorts in a single string: print Python has both single ' and double \ quotation marks. print 'Python has both single \' and double quotation marks.' (2) Python is not Pascal, or whatever language you seem to be writing in the style of. You almost never should write for-loops like this: for i in range(len(something)): print something[i] Instead, you should just iterate over something directly: for obj in something: print obj If you also need the index, use the enumerate function: for i,obj in enumerate(something): print obj, i If you are forced to use an ancient version of Python without enumerate, do yourself a favour and write your loops like this: for i in range(len(something)): obj = something[i] print obj, i instead of repeatedly indexing the list over and over and over and over again, as you do in your own code. The use of a temporary variable makes the code much easier to read and understand. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Regular expressions
Thanks a lot everyone. Can anyone suggest a good place to learn REs? Start with the manual: http://docs.python.org/py3k/library/re.html#module-re -- http://mail.python.org/mailman/listinfo/python-list
Daemon management
Dear list, Lately, I've had a personal itch to scratch, in that I run a couple of Python programs as daemons, and sometimes want to inspect or alter them in ad-hoc ways, or other times need to do things to them that are less ad-hoc in nature, but nevertheless lack a natural user interface. In order to solve that problem, I wrote a small library to allow the daemon to simply listen to some socket and accept arbitrary, but easily definable, commands. It also provides a remote REPL to allow me to run arbitrary Python code interactively in the context of the daemon. I was actually a bit surprised that I couldn't find any obvious existing solution to the problem, so I'm writing this message in order to share mine, just in case anyone else would happen to have the same problem as I had and doesn't want to reinvent the wheel yet again: http://www.dolda2000.com/~fredrik/pdm/ Humbly, Fredrik Tolf -- http://mail.python.org/mailman/listinfo/python-list
confused about __new__
I'm confused about the following. The idea here is that the set of instances of some class are small and finite, so I'd like to create them at class creation time, then hijack __new__ to simply return one of the preexisting classes instead of creating a new one each call. This seems to work in python3, but fails in python2 with: Foo(23) TypeError: unbound method __Foo__new__() must be called with Foo instance as first argument (got type instance instead) I don't understand. Can anyone explain? --rich class Foo(object): def __init__(self, val): self.val = val foos = [Foo(0), Foo(1)] def __Foo__new__(cls, val): if val 0x1: return foos[0] else: return foos[1] Foo.__new__ = __Foo__new__ Foo(23) -- http://mail.python.org/mailman/listinfo/python-list
Re: confused about __new__
On Mon, 26 Dec 2011 20:28:26 -0800, K. Richard Pixley wrote: I'm confused about the following. The idea here is that the set of instances of some class are small and finite, so I'd like to create them at class creation time, then hijack __new__ to simply return one of the preexisting classes instead of creating a new one each call. I'm surprised it works in Python3. Try this in Python 2 instead: Foo.__new__ = staticmethod(__Foo__new__) -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Regular expressions
On Mon, 26 Dec 2011, mauricel...@acm.org wrote:
I've tried
re.sub('@\S\s[1-9]:[A-N]:[0-9]', '@\S\s', '@HWI-ST115:568:B08LLABXX:
1:1105:6465:151103 1:N:0:')
but it does not seems to work.
Indeed, for several reasons. First of all, your backslash sequences are
interpreted by Python as string escapes. You'll need to write either \\S
or r\S (the r, for raw, turns off backslash escapes).
Second, when you use only \S, that matches a single non-space character,
not several; you'll need to quantify them. \S* will match zero or more,
\S+ will match one or more, \S? will match zero or one, and there are
a couple of other possibilities as well (see the manual for details). In
this case, you probably want to use + for most of those.
Third, you're not marking the groups that you want to use in the
replacement. Since you want to retain the entire string before the space,
and the numeric element, you'll want to enclose them in parentheses to
mark them as groups.
Fourth, your replacement string is entirely wacky. You don't use sequences
such as \S and \s to refer back to groups in the original text, but
numbered references, to refer back to parenthesized groups in the order
they appear in the regex. In accordance what you seemed to want, you
should probably use @\1/\2 in your case (\1 refers back to the first
parentesized group, which you be the first \S+ part, and \2 to the
second group, which should be the [1-9]+ part; the at-mark and slash
are inserted as they are into the result string).
Fifth, you'll probably want to match the last colon as well, in order not
to retain it into the result string.
All in all, you will probably want to use something like this to correct
that regex:
re.sub(r'@(\S+)\s([1-9]+):[A-N]+:[0-9]+:', r'@\1/\2',
'@HWI-ST115:568:B08LLABXX:1:1105:6465:151103 1:N:0:')
Also, you may be interested to know that you can use \d instead of
[0-9].
--
Fredrik Tolf
--
http://mail.python.org/mailman/listinfo/python-list
Re: Multithreading
On Dec 26, 2011 4:13 PM, Yigit Turgut y.tur...@gmail.com wrote: Why is there N variable in write_data function ? N is related to timer.tick(N) which is related to display function ? time.sleep(N) will pause writing to file for specified amount of time which is exactly what I am trying to avoid. My understanding from your first post was that the pygame loop was supposed to run at X FPS while the other loop was supposed to run every N seconds. If that is not the case and the data loop is supposed to run as fast as possible, then you don't need threads for this. Just stream the data in a tight loop, and on each iteration check the timer for how much time has elapsed to determine whether to run the pygame code without using timer.tick. If not enough time has elapsed for your target framerate, just skip that part. -- http://mail.python.org/mailman/listinfo/python-list
Re: confused about __new__
On 12/26/11 20:53 , Steven D'Aprano wrote: On Mon, 26 Dec 2011 20:28:26 -0800, K. Richard Pixley wrote: I'm confused about the following. The idea here is that the set of instances of some class are small and finite, so I'd like to create them at class creation time, then hijack __new__ to simply return one of the preexisting classes instead of creating a new one each call. I'm surprised it works in Python3. Try this in Python 2 instead: Foo.__new__ = staticmethod(__Foo__new__) Excellent. Thank you. --rich -- http://mail.python.org/mailman/listinfo/python-list
Re: confused about __new__
On Mon, 26 Dec 2011, K. Richard Pixley wrote: I don't understand. Can anyone explain? I'm also a bit confused about __new__. I'd very much appreciate it if someone could explain the following aspects of it: * The manual (http://docs.python.org/reference/datamodel.html) says that __new__ is a static method (special-cased so you need not declare it as such). What does special-cased mean? Apparently, for instance, in OP's case, Python did not automatically detect that it should not be bound as a method. * Is there any part of the manual that explains, holistically, the greater context of object instantiation into which __new__ fits? I can only find small parts of it spread around the documentation for __new__ and __init__, but no complete explanation of it. There are several things I'm wondering about, like what it means to call a type object at all; how methods, properties and the like are bound; how pickle can instantiate a class without calling __init__; when and whether __dict__ is created and a couple of other things. Is there a complete documentation of the process anywhere that I haven't managed to find? -- Fredrik Tolf -- http://mail.python.org/mailman/listinfo/python-list
Re: Python education survey
On Dec 20, 10:58 am, Andrea Crotti andrea.crott...@gmail.com wrote: On 12/20/2011 03:51 AM, Raymond Hettinger wrote: Do you use IDLE when teaching Python? If not, what is the tool of choice? Students may not be experienced with the command-line and may be running Windows, Linux, or Macs. Ideally, the tool or IDE will be easy to install and configure (startup directory, path, associated with a particular version of Python etc). Though an Emacs user myself, I've been teaching with IDLE because it's free; it runs on multiple OSes, it has tooltips and code colorization and easy indent/dedent/comment/uncomment commands, it has tab completion; it allows easy editing at the interactive prompt; it has an easy run-script command (F5); it has direct access to source code (File OpenModule) and a class browser (Cntl+B). On the downside, some python distros aren't built with the requisite Tcl/Tk support; some distros like the Mac OS ship with a broken Tcl/Tk so users have to install a fix to that as well; and IDLE sometimes just freezes for no reason. It also doesn't have an easy way to specify the startup directory. If your goal is to quickly get new users up and running in Python, what IDE or editor do you recommend? Raymond I think ipython and a good editor gives a much nicer experience than IDLE, which I actually almost never used, and for everything else there is python and python-mode. New users however can be pointed to something like PyCharm or Eclipse+PyDev if they are more familiar to IDEs.. I agree; IPython is a excellent choice. You have a much more powerful interactive Python experience, with all the features you need from an IDE. You can use any editor (VIM) and you can also readily hack IPython to death. I think the fact that anyone with basic programming skills can substantially enhance their console is a big winner in CS education. It gives students something they personally value to work on, it's a place to store all their little bits of code and actually benefit from them in real life. I've never met a programmer that got familiar with IPython and then went on to stop using it. It should be included in the standard library and used as the default Python interactive environment. The last line of my .bashrc file: ipython3 -- http://mail.python.org/mailman/listinfo/python-list
Re: Python education survey
On Dec 25, 5:44 pm, Rick Johnson rantingrickjohn...@gmail.com wrote: On Dec 19, 9:51 pm, Raymond Hettinger raymond.hettin...@gmail.com wrote: Do you use IDLE when teaching Python? If not, what is the tool of choice? I believe IDLE has the potential to be a very useful teaching tool and even in it's current abysmal state, i find it to be quite useful. Students may not be experienced with the command-line and may be running Windows, Linux, or Macs. Ideally, the tool or IDE will be easy to install and configure (startup directory, path, associated with a particular version of Python etc). Why install an IDE when IDLE is already there? Oh, yes, IDLE SUCKS. I know that already. But this revelation begs the question... Why has this community allowed IDLE to rot? Why has guido NOT started a public discussion on the matter? Though an Emacs user myself, I've been teaching with IDLE because it's free; it runs on multiple OSes, it has tooltips and code colorization and easy indent/dedent/comment/uncomment commands, it has tab completion; it allows easy editing at the interactive prompt; it has an easy run-script command (F5); it has direct access to source code (File OpenModule) and a class browser (Cntl+B). Yes, IDLE has all the basic tools anyone would need. Some people complain about a debugger, but i never use a debugger anyway. I feel debuggers just wreaken your debugging skills. On the downside, some python distros aren't built with the requisite Tcl/Tk support; And who's fault is that? some distros like the Mac OS ship with a broken Tcl/Tk so users have to install a fix to that as well; and IDLE sometimes just freezes for no reason. And who's fault is that? [IDLE] also doesn't have an easy way to specify the startup directory. Are you kidding me? That could be fixed so easily! If your goal is to quickly get new users up and running in Python, what IDE or editor do you recommend? IDLE, of course. But NOT in its current state. Why would myself (or anyone) go to the trouble of downloading third party IDEs when IDLE is just waiting there for us to use? I for one, like to use tools that have open source code. And what is a better Python IDE than a Python IDE written in PYTHON? I ask ya? Also, what is the purpose of this thread Raymond? Are you (and others) considering removing IDLE from the source distro? You know. Many folks in this community have known for a long time how much i love IDLE, but at the same time how much i loath it's atrocious code base. I also know for a fact, that many movers and shakers within this community simultaneously use IDLE, and want to see IDLE code improved. However. None of these fine folks have taken the time to contact me privately so we can discuss such an evolution. Why is that? It boggles the mind really. Do people seriously use IDLE? I thought it was just there for scratchers, like turtle. -- http://mail.python.org/mailman/listinfo/python-list
python logging module:a quick question
Hello all: I have a basic server I am working on, and wanted some input with an error I'm getting. I am initializing the logger like so: if __name__ == __main__: observer = log.PythonLoggingObserver() observer.start() logging.basicConfig(filename='logs/server.log', level=logging.DEBUG, format='%(asctime)s [%(levelname)s] %(module)s:%(funcname)s:%(lineno)d %(message)s') logger = logging.getLogger() logger.addHandler(logging.handlers.TimedRotatingFileHandler) ... I get the following error: File /home/gserver/alpine/lib/python2.7/site-packages/twisted/internet/protoc ol.py, line 52, in doStart log.msg(Starting factory %r % self) --- exception caught here --- File /home/gserver/alpine/lib/python2.7/site-packages/twisted/python/log.py, line 284, in msg self.observers[i](actualEventDict) File /home/gserver/alpine/lib/python2.7/site-packages/twisted/python/log.py, line 532, in emit self.logger.log(level, text) File /usr/local/lib/python2.7/logging/__init__.py, line 1195, in log self._log(level, msg, args, **kwargs) File /usr/local/lib/python2.7/logging/__init__.py, line 1250, in _log self.handle(record) File /usr/local/lib/python2.7/logging/__init__.py, line 1260, in handle self.callHandlers(record) File /usr/local/lib/python2.7/logging/__init__.py, line 1299, in callHandler s if record.levelno = hdlr.level: exceptions.AttributeError: type object 'TimedRotatingFileHandler' has no attribute 'level' I'm also curious how this rotating handler works. Will it just log to a file per day for a week, then start rotating those out with newer ones? Can I change the interval? -- Take care, Ty Web: http://tds-solutions.net The Aspen project: a light-weight barebones mud engine http://code.google.com/p/aspenmud Sent from my toaster. -- http://mail.python.org/mailman/listinfo/python-list
Re: installing matplotlib in MacOs 10.6.8.
In article camw75ysaeawo5+rjwggfkustyto1q+0zfkvachtuadodqy4...@mail.gmail.com, Alex Ter-Sarkissov ater1...@gmail.com wrote: that's quite weird: if I run python2.7-32 in terminal, it works like you said, but when I add it as an interpreter in Eclipse, matplotlib.pyplot doesn't get imported for some reason. Even more strange, either way platform.architecture() reports 64-bit. What's wrong here? platform.architecture() is not accurate for OS X 64-/32-bit builds. Use sys.maxsize instead. I have no experience with Eclipse so I really can't say how Eclipse might be launching the interpreter. Sorry! -- Ned Deily, n...@acm.org -- http://mail.python.org/mailman/listinfo/python-list
Re: confused about __new__
On Mon, Dec 26, 2011 at 10:48 PM, Fredrik Tolf fred...@dolda2000.com wrote: I'm also a bit confused about __new__. I'd very much appreciate it if someone could explain the following aspects of it: * The manual (http://docs.python.org/reference/datamodel.html) says that __new__ is a static method (special-cased so you need not declare it as such). What does special-cased mean? Apparently, for instance, in OP's case, Python did not automatically detect that it should not be bound as a method. It apparently has to do with the class creation. For the special-casing to happen, the __new__ method has to be present when the class is created. If it is, then it automatically gets wrapped in a staticmethod. In the OP's case, he was adding the __new__ method after class creation, so the wrapping did not happen automatically. Compare: def my_new(cls): return object.__new__(cls) ... class Foo(object): ... __new__ = my_new ... class Bar(object): pass ... Bar.__new__ = my_new Foo.__dict__['__new__'] staticmethod object at 0x0237D6F0 Bar.__dict__['__new__'] function my_new at 0x02381430 * Is there any part of the manual that explains, holistically, the greater context of object instantiation into which __new__ fits? I can only find small parts of it spread around the documentation for __new__ and __init__, but no complete explanation of it. There are several things I'm wondering about, like what it means to call a type object at all; I don't know of anything that organizes it that way specifically, but I believe the Data Model reference pretty much covers what you're looking for. From the type hierarchy, under Callable Types: http://docs.python.org/reference/datamodel.html#the-standard-type-hierarchy Class Types Class types, or “new-style classes,” are callable. These objects normally act as factories for new instances of themselves, but variations are possible for class types that override __new__(). The arguments of the call are passed to __new__() and, in the typical case, to __init__() to initialize the new instance. AFAIK, that's pretty much it. When a type is called, __new__ is called to create the new instance, and then __init__ is called to initialize it (if __new__ returned an instance of the type). how methods, properties and the like are bound; When they're accessed, using the descriptor protocol, not as part of the instantiation process. See: http://docs.python.org/reference/datamodel.html#invoking-descriptors how pickle can instantiate a class without calling __init__; By calling the __new__ method directly instead of calling the type: http://docs.python.org/library/pickle.html#object.__getnewargs__ when and whether __dict__ is created and a couple of other things. Under the hood as part of the object creation process, unless the class uses __slots__. -- http://mail.python.org/mailman/listinfo/python-list
Re: confused about __new__
On 12/27/2011 04:48 PM, Fredrik Tolf wrote: On Mon, 26 Dec 2011, K. Richard Pixley wrote: I don't understand. Can anyone explain? I'm also a bit confused about __new__. I'd very much appreciate it if someone could explain the following aspects of it: * The manual (http://docs.python.org/reference/datamodel.html) says that __new__ is a static method (special-cased so you need not declare it as such). What does special-cased mean? Apparently, for instance, in OP's case, Python did not automatically detect that it should not be bound as a method. If you declare new in the regular way: class Foo(object): def __new__(cls): ... Python would create __new__ as a static method even without applying the staticmethod decorator; that python does not detect to special case __new__ when it is added dynamically is probably an oversight in Python 2.x that was fixed in Python 3.x. -- http://mail.python.org/mailman/listinfo/python-list
[issue13663] pootle.python.org is outdated.
New submission from INADA Naoki songofaca...@gmail.com: I am one of Japanese translate of Python documents. We have done translating Python 2.7 document and will start translating Python 3.2 or 3.3. I want to use sphinx-i18n and pootle to translate. But http://pootle.python.org/ is very outdated. Anyone can update the site? If nobody maintain the site, could I create Python Document project at http://pootle.locamotion.org/ ? -- assignee: docs@python components: Documentation messages: 150261 nosy: docs@python, naoki priority: normal severity: normal status: open title: pootle.python.org is outdated. versions: Python 2.7, Python 3.2, Python 3.3, Python 3.4 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue13663 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue13508] ctypes' find_library breaks with ARM ABIs
Changes by Stefano Rivera pyt...@rivera.za.net: -- nosy: +stefanor ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue13508 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue12760] Add create mode to open()
Devin Jeanpierre jeanpierr...@gmail.com added the comment: C11 uses 'x' for this, for what it's worth. This is not a duplicate issue. The openat solution is no easier than the os.open solution. -- nosy: +Devin Jeanpierre ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue12760 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue13508] ctypes' find_library breaks with ARM ABIs
Changes by Barry A. Warsaw ba...@python.org: -- nosy: +barry ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue13508 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue12463] Calling SocketServer.shutdown() when server_forever() was not called will hang
Michael P. Reilly arc...@gmail.com added the comment: Here is a patch to socketserver.py which can be applied to 2.6, 2.7 and 3.2. The fix is for BaseServer, ForkingMixIn and ThreadingMixIn. All three now correctly respond to the shutdown method. I have no way of testing Windows or MacOSX (based on docs, MacOSX should work without changes); the ForkingMixIn will raise an AssertionError on non-POSIX systems. There may be a better way of handling non-POSIX systems, but again, I'm not able to test or develop at this time. I'll also update the simpletest.py script. -- versions: +Python 3.2 Added file: http://bugs.python.org/file24093/socketserver.patch ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue12463 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue12463] Calling SocketServer.shutdown() when server_forever() was not called will hang
Michael P. Reilly arc...@gmail.com added the comment: An update test program. Execute with appropriate PYTHONPATH (to dir to patched module and explicit interpreter executable: PYTHONPATH=$PWD/2.7/b/Lib python2.7 $PWD/simpletest.py -- Added file: http://bugs.python.org/file24094/simpletest.py ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue12463 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue13664] UnicodeEncodeError in gzip when filename contains non-ascii
New submission from Jason R. Coombs jar...@jaraco.com: While investigating #11638, I encountered another encoding issue related to tarballs. Consider this command: python -c import gzip; gzip.GzipFile(u'\xe5rchive', 'w', fileobj=open(u'\xe5rchive', 'wb')) When run, it triggers the following traceback: Traceback (most recent call last): File string, line 1, in module File c:\python\lib\gzip.py, line 127, in __init__ self._write_gzip_header() File c:\python\lib\gzip.py, line 172, in _write_gzip_header self.fileobj.write(fname + '\000') UnicodeEncodeError: 'ascii' codec can't encode character u'\xe5' in position 0: ordinal not in range(128) Based on the resolution of #13639, I believe the recommended fix is to handle unicode here much like Python 3 does--specifically, detect unicode, encode to 'latin-1' if possible or leave the filename blank if not. -- messages: 150265 nosy: jason.coombs priority: low severity: normal status: open title: UnicodeEncodeError in gzip when filename contains non-ascii versions: Python 2.7 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue13664 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue13664] UnicodeEncodeError in gzip when filename contains non-ascii
Changes by Jason R. Coombs jar...@jaraco.com: -- components: +Library (Lib) ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue13664 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue11638] python setup.py sdist --formats tar* crashes if version is unicode
Jason R. Coombs jar...@jaraco.com added the comment: I've captured the cause of the UnicodeEncodeErrors as #13664. After rebasing the changes to include the fix for #13639, I found that the tests were still failing until I also reverted the patch to call tarfile.open with 'w:gz'. Now all the new tests pass (with no other changes to the code). This latest patch only contains tests to capture the errors encountered. I plan to push this changeset and also port the test changes the default (Python 3.3) branch. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11638 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue11638] python setup.py sdist --formats tar* crashes if version is unicode
Changes by Jason R. Coombs jar...@jaraco.com: Added file: http://bugs.python.org/file24095/dc1045d08bd8.diff ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11638 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue13639] UnicodeDecodeError when creating tar.gz with unicode name
Roundup Robot devn...@psf.upfronthosting.co.za added the comment: New changeset dc1045d08bd8 by Jason R. Coombs in branch '2.7': Issue #11638: Adding test to ensure .tar.gz files can be generated by sdist command with unicode metadata, based on David Barnett's patch. http://hg.python.org/cpython/rev/dc1045d08bd8 -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue13639 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue11638] python setup.py sdist --formats tar* crashes if version is unicode
Roundup Robot devn...@psf.upfronthosting.co.za added the comment: New changeset dc1045d08bd8 by Jason R. Coombs in branch '2.7': Issue #11638: Adding test to ensure .tar.gz files can be generated by sdist command with unicode metadata, based on David Barnett's patch. http://hg.python.org/cpython/rev/dc1045d08bd8 -- nosy: +python-dev ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11638 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue11638] python setup.py sdist --formats tar* crashes if version is unicode
Roundup Robot devn...@psf.upfronthosting.co.za added the comment: New changeset f0fcb82a88e9 by Jason R. Coombs in branch 'default': Ported some test cases from 2.7 for #11638 http://hg.python.org/cpython/rev/f0fcb82a88e9 -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11638 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue11638] python setup.py sdist --formats tar* crashes if version is unicode
Jason R. Coombs jar...@jaraco.com added the comment: Since the tests now pass, and the only changes were to the tests, I've pushed them to the master. And with that I'm marking this ticket as closed. -- status: open - closed ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue11638 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue13665] TypeError: string or integer address expected instead of str instance
New submission from Jason R. Coombs jar...@jaraco.com:
When constructing a ctypes.c_char_p with a unicode string, a confusing error
message is reported:
python -c import ctypes; ctypes.c_char_p('foo')
Traceback (most recent call last):
File string, line 1, in module
TypeError: string or integer address expected instead of str instance
Since string and str seem like essentially the same thing, the error
message doesn't make sense.
This message is obviously due to the change to unicode as the default string
instance in Python 3. The error message should probably be updated to read
bytes or integer address expected instead of a str instance.
It's probably also worth scanning through the ctypes codebase for similar
messages.
--
components: ctypes
messages: 150271
nosy: jason.coombs
priority: low
severity: normal
status: open
title: TypeError: string or integer address expected instead of str instance
versions: Python 3.2, Python 3.3
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[issue13666] datetime documentation typos
New submission from Stephen Kelly steve...@gmail.com: There are several bugs on http://docs.python.org/library/datetime.html Section 8.1.6 references the method rzinfo.dst(), which does not exist. Presumably this should be tzinfo.dst(). Section 8.1.4 contains an implementation of a GMT2 timezone. There seems to be a bug in the utcoffset() and dst() implementations. The timedelta(hours=2) is in the dst() implementation, but it should be in the uctoffset() implementation. The docs for tzinfo.utcoffset() start with 'Return offset of local time from UTC, in minutes east of UTC'. Other methods (eg dst()) also document that the unit to return should be 'minutes'. However, all code samples instead return a timedelta. The documentation I quoted should instead read 'Return offset of local time from UTC as a timedelta, or None'. -- assignee: docs@python components: Documentation messages: 150272 nosy: docs@python, steveire priority: normal severity: normal status: open title: datetime documentation typos versions: Python 2.6 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue13666 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
