Re: Using wild character
On Thu, 06 Sep 2007 16:48:31 -0700, Zentrader wrote:
On Sep 6, 12:47 am, Marc 'BlackJack' Rintsch [EMAIL PROTECTED] wrote:
On Wed, 05 Sep 2007 22:54:55 -0700, TheFlyingDutchman wrote:
To do a *string wildcard filter use the endswith() function instead
of startswith() and to do a *string* type wildcard filter use
the find() function -1.
Maybe better the ``in`` operator for the '*string*' type. `str.find()`
will go away in the future.
string.find serves a useful purpose in that it returns the starting
location of the string found, or -1 if not found, so if you wanted to
slice abdecf onc, string.find will tell you where that is.
But that position is not needed here and I think::
result = [name for name in names if 'spam' in name]
reads more natural than::
result = [name for name in names if name.find('spam') -1]
Ciao,
Marc 'BlackJack' Rintsch
--
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Re: startswith( prefix[, start[, end]]) Query
Else, you could as well write your own testing function: def str_starts_with(astring, *prefixes): startswith = astring.startswith for prefix in prefixes: if startswith(prefix): return true return false What is the reason for startswith = astring.startswith startswith(prefix) instead of astring.startswith(prefix) -- http://mail.python.org/mailman/listinfo/python-list
Re: Python and CUDO
On Sep 6, 10:12 pm, Robert Kern [EMAIL PROTECTED] wrote: Veronika Lindstrand Kant wrote: Hi! I just wonder if there are any plans for building any support using NIVIDAS CUDO plattform into python? Not into Python itself, but we are working on interfacing with NVIDIA's CUDA, yes (presuming you actually meant NVIDIA's CUDA rather than NIVIDAS CUDO). http://code.google.com/p/pystream/ -- Robert Kern I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth. -- Umberto Eco Maybe you and the CorePy guys at http://www.corepy.org/ could swap notes and give us a similar way to work with these accellerators? - Paddy. -- http://mail.python.org/mailman/listinfo/python-list
How to convert None to null value
Hi ,
i am trying to insert records from one table to another table in postgres
sql using the the following code
posConn.query(insert into
usr(usr_id,usr_name,usr_passwd,grp_cde,usr_type,usr_chk_till_val, \
usr_active,usr_daily_auth,usr_lst_login,usr_lst_logout,usr_shift_id,usr_role_level)
values \
('%s','%s','%s',%s,%i,%d,'%s',%i,%i,%i,%i,%i)
%(row[0],row[1],row[2],row[3],row[4],row[5], \
row[7],row[8],row[10],row[11],row[12],row[14]) )
here row[4] column is having null value so python consides it as None but
will insert into the table it inserts as None not null value
please help how to convert None to null value
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Re: unexpected behavior: did i create a pointer?
gu wrote: hi to all! after two days debugging my code, i've come to the point that the problem was caused by an unexpected behaviour of python. or by lack of some information about the program, of course! i've stripped down the code to reproduce the problem: [snip FAQ] Yes, basically you *created* a pointer. That's all that python has: pointers. When saying a = AnyOldObject() b = a then 'a' and 'b' are different /names/ for the /very same/ object (try a is b, or id(a)==id(b)). This is really a FAQ (once a week or so?), but for the life of me I can't find the right words for a google query. TO THE TROOP: What keywords would you attach to that question? /W -- http://mail.python.org/mailman/listinfo/python-list
Re: unexpected behavior: did i create a pointer?
gu schreef: copyOfA = a now, in the second for cycle and in functionA() i only 'touch' copyOfA (altering it). copyOfA isn't a copy of a; it's a different name bound to the same object as a. You can verify that: id(a) and id(copyOfA) will return the same value. To make a copy of a (assuming a is a dict), you can do: copyOfA = dict(a) or copyOfA = a.copy() or more generally import copy copyOfA = copy.copy(a) Cheers, Roel -- If I have been able to see further, it was only because I stood on the shoulders of giants. -- Isaac Newton Roel Schroeven -- http://mail.python.org/mailman/listinfo/python-list
Re: unexpected behavior: did i create a pointer?
On Fri, 07 Sep 2007 10:40:47 +, Steven D'Aprano wrote: Nor does it include peek and poke commands for reading and writing into random memory locations. I guess `ctypes` offers tools to write `peek()` and `poke()`. :-) Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: So what exactly is a complex number?
Grzegorz S?odkowicz wrote: Interesting. It appears that we are ran into a mathematical cultural difference. Were I come from vectors *are* defined as having four properties that I enumerated. After some research I found that English sources (Wikipedia) indeed give the definition you supplied. Indeed, interesting. However, given the following problem: (assuming 2-d Cartesian coordinate system and gravity acting 'downwards') There are 3 point masses: 2 kg at (0, 0), 1 kg at (5, 4) and 4 kg at (2, 2). The acting forces are given as vectors: [2, 2] [1, 1]. Find the trajectories of all point masses. how would you propose to solve it without knowing where the forces are applied? I didn't say that you must not know the point of application, but I said that it was not a property of the vector itself. It is true, however, that in physical calculations you should not mix many types of vectors (like force) that are, in the experiment, applied to different points of application. Again, I think we were given different definitions. Mine states that direction is 'the line on which the vector lies', sense is the 'arrow' and magnitude is the 'length' (thus non-negative). The definition is separate from mathematical description (which can be '[1 1] applied at (0, 0)' or 'sqrt(2) at 45 deg applied at (0, 0)' or any other that is unambiguous). Oh, I thought we were talking about quite mathematical vectors? In physics, I learned that a vector is only what transforms like a vector. Represent the direction as one number? Only in a one-dimensional space. No. In one-dimensional 'space' direction is a ± quantity (a 'sense'). In 2-d it can be given as an angle. Indeed, you're right. So, those vectors have different properties depending on the used coordinate system? I myself prefer the concise definition ... Regards, Björn -- BOFH excuse #128: Power Company having EMP problems with their reactor -- http://mail.python.org/mailman/listinfo/python-list
Re: Any syntactic cleanup likely for Py3? And what about doc standards?
On 7 Sep, 06:19, Kay Schluehr [EMAIL PROTECTED] wrote: On Sep 6, 12:56 pm, Paul Boddie [EMAIL PROTECTED] wrote: I think there's been a widespread kitchen sink mentality around the Python language for some time, which is where the multimethods proposal, amongst others, fits in here. Maybe that's one of two fixed points in the evolution of a programming language? The other one might be an almost non-designed and small language with a vast and flat library a la PHP and Zend. Apparently even Scheme moves into the kitchen sink today with the new R6RS specification. My impression of PHP (before version 5), derived from anecdotes and general criticism, is that both the language and the most promoted libraries have accumulated features without much regard to how the end- user experience works out. In contrast, it is said that Python has been improved with more attention to the end-user experience (albeit with limitations related to the main implementation and backwards compatibility), with Python 3000 being the pinnacle of this user- centric process. Regardless of whether Python 3000 really tidies up the experience, it is notable that the promotional value of the standard library has diminished, perhaps because the core developers no longer feel that the language attracts embarrassing criticism which is best answered by deflecting the critic to standard library solutions. Python is going to be the-right-thing with abandoning the print statement or making lists a bit more monotyped with a type aware sort. The worse-is-better philosophy on the other hand is indifferent towards stylistic consistency and equipped with less nominalistic pedantry ( this is a list and therefore you only have to use it as a list and not as a multiset... ). I think you've swum into the philosophical deep end on this point. ;-) But of the different articles on the PythonWarts page I mentioned, Mertz's criticisms (which include notes on sorting heterogeneous collections) are certainly worth reading, partly because they do highlight awkward-to-address end-user expectations whilst being fairly modern criticisms. That's not to say that I agree with everything he writes, although I have some sympathy with his opinions on iterators vs. sequences and the current level of convenience in this area. This explains also the lack of interest into the std library which will be reduced to CPython services and basic datatypes. But there are also organizational issues and I don't even think that a lib that provides applications and domain specific services has to be necessarily maintained and approved by python-dev. I'd go even further and contend that's one of the issues where a rather large community such as Pythons could grow up and set code review standards ( and I mean *manual* code reviews of conscientous readers. I don't mean cheesecake or up(down)moddings in Web 2.0 style, implementing the wisdom of the crowd ). I can even live with Eggs and a not-so-common code base but not with low quality. Once upon a time I wrote some thoughts down about marketing Python where one considers a number of things as the product or solution. Certainly, in earlier times, adding stuff to the standard library was a way of positioning Python as a solution to problems in particular domains: if you needed to write a mail client, for example, Python provided a working solution as standard that would potentially be enough to persuade people to use Python for such a project. The belief that modules should be included in the standard library is a continuation of this positioning or advocacy-related sentiment, as well as being an issue of convenience, of course. As technical issues start to encourage other models for providing solutions based on Python, one has to consider the social aspects of such models. Where something in the standard library should have an implicit stamp of approval, although opinions are divided on whether some modules deserve their place, other models need to support notions of approval, credibility, quality, and so on. And there we have different approaches: repositories (optionally with rankings, noticing that Ubuntu seems to be adding support for such things), megaframeworks (where people effectively recommend a combination of solutions), heavy distributions (with a selection of popular packages in an enlarged standard library). In my opinion, such wider work on promoting Python's usability is possibly more beneficial to both potential and existing elements of the community than merely polishing the language and hoping that people are motivated to write great code because of the increased elegance. Paul -- http://mail.python.org/mailman/listinfo/python-list
Best practice prompting for password
Hi, what's the best practice to securely prompt user for password on console in Python? IIRC some programs like SSH do a lot to ensure that the input comes from TTY and is not redirected from somewhere and several other checks. In the case of OpenSSH even the password prompt is always displayed regardless if the output is redirected to a file or not. Any pointers to best practice or code snippet of python password prompt? Thanks Gibo -- http://mail.python.org/mailman/listinfo/python-list
Re: Class design (information hiding)
Bruno Desthuilliers schrieb: Nope. It's either 'interface' (no leading underscore), 'implementation' (single leading underscore), 'implementation with some protection against accidental overriding' (two leading underscores). What do you mean with 'implementation'? What does it express? -- http://mail.python.org/mailman/listinfo/python-list
Re: unexpected behavior: did i create a pointer?
On 2007-09-07, Peter Otten [EMAIL PROTECTED] wrote: Am Fri, 07 Sep 2007 10:40:47 + schrieb Steven D'Aprano: Python doesn't have any pointers. Thinking of python variables or names as pointers should get you a long way when trying to understand python's behaviour. But thinking of them as names bound to objects will get you further (and get you there faster). ;) As long as you keep in mind that python doesn't have pointers to pointers, and no pointer arithmetic either... -- Grant Edwards grante Yow! Hello... IRON at CURTAIN? Send over a visi.comSAUSAGE PIZZA! World War III? No thanks! -- http://mail.python.org/mailman/listinfo/python-list
Re: wxPython unexpected exit
On Sep 7, 3:10 am, Jimmy [EMAIL PROTECTED] wrote:
Hi, wxPython is cool and easy to use, But I ran into a problem
recently when I try to write a GUI.
The thing is I want to periodically update the content of StatixText
object, so after create them, I pack them into a list...the problem
comes when I later try to extract them from the list! I don't know
why?
my code is as following:
import wx, socket
import thread
class MyFrame(wx.Frame):
firstrun = 0
def __init__(self):
wx.Frame.__init__(self, None, -1, 'Notifier')
self.panel = wx.Panel(self, -1)
self.length = 50
self.scale = 0.6
self.count = 5
self.size = wx.Frame.GetSize(self)
self.distance = self.size[1] / self.count
self.labellist = []
self.gaugelist = []
def ParseAndDisplay(self, data):
print Successful access to main Frame class
print 'And receive data: ', data
if MyFrame.firstrun == 0:
print 'First time run'
items = 3
for i in range(items):
self.labellist.append(wx.StaticText(self.panel, -1, data+str(i),
(150, 50+i*20), (300,30)))
MyFrame.firstrun = 1
else:
self.labellist[0].SetLabel('AAA')//PROGRAM WILL ABORT
HERE!!!
self.labellist[1].SetLabel(Guo)
self.labellist[2].SetLabel(Qiang)
class NetUdp:
def __init__(self):
self.port = 8081
self.s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
self.s.bind((, self.port))
print Listening on port, self.port
def recvdata(self):
data, addr = self.s.recvfrom(1024)
return data
def netThread():
netudp = NetUdp()
while True:
data = netudp.recvdata()
frame.ParseAndDisplay(data)
if __name__ == '__main__':
firstrun = 0
app = wx.PySimpleApp()
frame = MyFrame()
frame.Show()
# start network thread first
id = thread.start_new_thread(netThread, ())
# main wxpython loop begins
app.MainLoop()
I know the code is ugly, but can anyone really save me here!
If you use threads that update the GUI, you need to take a look at the
following wiki page:
http://wiki.wxpython.org/LongRunningTasks
I've used the techniques therein and they *just work*. I'm not sure if
you can set values on items in a list or not. I've tried that sort of
thing and sometimes it works and sometimes it doesn't.
The wxPython group is probably the best place to ask these questions
anyway: http://www.wxpython.org/maillist.php
Mike
--
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Re: Using s.sort([cmp[, key[, reverse]]]) to sort a list of objects based on a attribute
On Fri, 07 Sep 2007 06:57:35 -0700, cjt22 wrote: I have a step class and store in a list step instances A step instance contains variables: name, startTime etc and startTime is stored as a string %H:%M:%S What I would like to do is to be able to sort this list of objects based on the startTime object so that the first item in the list is the object with the earliest Start time and last item is the object with the last Start time. I belive my key has to be = strpTime(step.sTime, %H:%M:%S) But don't know how to create the comparison funciton. Any help on how I can perform this whole operation would be much appreciated. This should be enough:: steps.sort(key=lambda s: s.startTime) If you sort strings of the form 'hh:mm:ss' the represented times are sorted chronological. No need to convert them to a number first. If the natural sort criterion for `Step` objects is the start time you might override `__cmp__()` of `Step`\s instead:: def __cmp__(self, other): return cmp(self.startTime, other.startTime) Now you can just sort the list with ``steps.sort()``. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
RE: application version checking against database
From: imageguy We are trying to implement a system that checks the version of the application against a version number stored in the database. We don't want the app and the db don't become out of sync. We have tried setting a __version__ variable in the top most module, however, it seems that this is not accessible for the modules that are subsequently imported. There are a several locations in the app where we want to do the version check, but we would like to have one place to set the version number, namely the top level module. We have thought of creating a Version class and passing it around, but aren't really keen on that idea. Any suggestions/ideas would be helpful. NOTE: the app is developed in wxPython. You could add a Version module that contains the version number and any functions related to the version checking, and import that into the modules that do version checking. -- -Bill Hamilton -- http://mail.python.org/mailman/listinfo/python-list
Re: Class design (information hiding)
On Fri, 07 Sep 2007 15:17:06 +0200, Alexander Eisenhuth wrote: Bruno Desthuilliers schrieb: Nope. It's either 'interface' (no leading underscore), 'implementation' (single leading underscore), 'implementation with some protection against accidental overriding' (two leading underscores). What do you mean with 'implementation'? What does it express? I guess he meant 'implementation detail', i.e. someone other then the author of the class should not use until he really knows the implementation and that this all might change without notice in the next release. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Checking if elements are empty
Steven D'Aprano wrote: On Fri, 07 Sep 2007 11:12:05 +0200, Wildemar Wildenburger wrote: Lawrence D'Oliveiro wrote: In message [EMAIL PROTECTED], Chris Mellon wrote: On 9/5/07, Steve Holden [EMAIL PROTECTED] wrote: Doran, Harold wrote: Is there a way to check if the first element of y is null? len(y[0]) == 0 Better spelled as if y[0]: Not a good idea. Why not? What happens if y is an empty list? An exception pops up, of course ;). It all depends on the (intended) semantics of the program; the original question sounds like that list is supposed to have at least one element at that point, so there is no problem. And if it's not then that has to be dealt with, but that is not the problem here. So the usual way to check if the first element of a list y is True in a boolean context is indeed if y[0]: (or for False of course if not y[0]:). /W -- http://mail.python.org/mailman/listinfo/python-list
Re: exponential float formmating
On Fri, 07 Sep 2007 06:08:19 -0700, zunbeltz wrote:
For compatibility reasons with an old program I have to format string
in exponential format with the following format
0.xE-yy
This means that the number start always by 0 and after the exponent
there should be alway the sing and 2 number for the exponent.
for example 13 shoud be 0.13000E+02
I always get 1.3E001
I don't know if this is platform dependent but this works for me:
In [41]: '%e' % 1.3
Out[41]: '1.30e+00'
In [42]: ('%e' % 1.3).upper()
Out[42]: '1.30E+00'
Ciao,
Marc 'BlackJack' Rintsch
--
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Re: Finding specific date ranges
On Sep 7, 2:47 am, Tim Golden [EMAIL PROTECTED] wrote: Zentrader wrote: On Sep 6, 7:56 am, [EMAIL PROTECTED] wrote: December 31, 2006January 13, 2007 # doesn't earn January 14, 2007January 27, 2007 # does earn January 28, 2007February 10, 2007 # doesn't February 11, 2007 February 24, 2007 # does Am I over simplifying if I say that since it appears to be a two week pay period, the date has to be greater than the 11th unless the first, or first and second, are on a weekend, in which case it would be 12 or 13? Or a reasonable facsimile thereof, depending on whether or not the two week period is Saturday through Friday. I think it's one of those things where the neatest answer could well depend on the sort of heuristic you mention. As a rule, when I come across this kind of requirement, I tend to put the most general solution in place, unless a *real* optimisation is clearly called for. In my experience, this makes it much easier for the next person who looks at the code, typically years later, even if that's me! (This is has just happened to me this week, having to review a date-related calculation to do the repost frequency of the adverts my company deals with. I wrote the original code five years ago, and commented it intelligently, but I *still* had to work through the code twice when we had a problem with a particular cycle!) TJG I think it's foolish NOT to comment code unless it's very well self- documented. Even then, a couple lines of comments can be helpful. I've had to translate a bunch of Kixtart code into Python and none of it was commented and it wasn't well formed code either. And I've had the same thing happen with code that's only a year old. I'll read it and then go what the?! It's just not possible to remember every line of code you write. I wish it was. Mike -- http://mail.python.org/mailman/listinfo/python-list
Re: Class design (information hiding)
On 9/7/07, Alexander Eisenhuth [EMAIL PROTECTED] wrote: Bruno Desthuilliers schrieb: Nope. It's either 'interface' (no leading underscore), 'implementation' (single leading underscore), 'implementation with some protection against accidental overriding' (two leading underscores). What do you mean with 'implementation'? What does it express? Don't touch my _members, they're my private parts! If you do, face the consequences! Again, this isn't enforced by the language (other than the slight name mangling on __names), but a convention that python programmers should adhere to. -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: Finding specific date ranges
On Sep 6, 6:41 pm, Zentrader [EMAIL PROTECTED] wrote: On Sep 6, 7:56 am, [EMAIL PROTECTED] wrote: December 31, 2006January 13, 2007 # doesn't earn January 14, 2007January 27, 2007 # does earn January 28, 2007February 10, 2007 # doesn't February 11, 2007 February 24, 2007 # does Am I over simplifying if I say that since it appears to be a two week pay period, the date has to be greater than the 11th unless the first, or first and second, are on a weekend, in which case it would be 12 or 13? Or a reasonable facsimile thereof, depending on whether or not the two week period is Saturday through Friday. Yeah it is a 2-week period, but the starting day can change depending on whether or not you're salaried. I haven't even looked at how we handle unions. Ugh. But yes, you are correct. Mike -- http://mail.python.org/mailman/listinfo/python-list
Re: py2exe - change name of exe created
On 2007-09-07, imageguy [EMAIL PROTECTED] wrote:
Note that every thing works fine with this and creates an exe
program called myprogram.exe
I would like to setup program to create an output called;
MyBestProgram.exe
IS that at all possible ?
ADD this to the end of your script:
import os
os.rename('dist/myprogram.exe','dist/MyBestProgram.exe')
--
Grant Edwards grante Yow! Zippy's brain cells
at are straining to bridge
visi.comsynapses ...
--
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Re: MySQLdb: ValueError Something Stupid
On Fri, 2007-09-07 at 05:52 -0700, mcl wrote:
ValueError: invalid literal for int(): 0-
args = ('invalid literal for int(): 0-',)
=
Thanks Richard
Sort of solved it.
On that particular table it did not like * for all fields.
Any reason why that would be the case ?
None that we can divine without more information. What's the schema for
the table in question, which column(s) are you excluding to make the
query work, and what kind of data is in the column(s) you're excluding?
--
Carsten Haese
http://informixdb.sourceforge.net
--
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Re: How to convert None to null value
On Fri, 2007-09-07 at 11:19 +0200, pradeep kumar wrote:
Hi ,
i am trying to insert records from one table to another table in
postgres sql using the the following code
posConn.query(insert into
usr(usr_id,usr_name,usr_passwd,grp_cde,usr_type,usr_chk_till_val, \
usr_active,usr_daily_auth,usr_lst_login,usr_lst_logout,usr_shift_id,usr_role_level)
values \
('%s','%s','%s',%s,%i,%d,'%s',%i,%i,%i,%i,%i)
%(row[0],row[1],row[2],row[3],row[4],row[5], \
row[7],row[8],row[10],row[11],row[12],row[14]) )
here row[4] column is having null value so python consides it as None
but will insert into the table it inserts as None not null value
please help how to convert None to null value
If you were using a DB-API compliant module, you should use parameter
binding instead of building query strings by hand:
http://informixdb.blogspot.com/2007/07/filling-in-blanks.html
However, nothing in DB-API has a .query method, so either you're using a
module that's not conforming to DB-API, or you're using some kind of
wrapper around a DB-API module. In any case, you should try to find out
how to do parameter binding with whatever it is you're using. If it
doesn't have a parameter binding mechanism, you should throw it away and
replace it with a DB-API complaint module.
HTH,
--
Carsten Haese
http://informixdb.sourceforge.net
--
http://mail.python.org/mailman/listinfo/python-list
Re: wxPython unexpected exit
Jimmy [EMAIL PROTECTED] wrote in message
news:[EMAIL PROTECTED]
Hi, wxPython is cool and easy to use, But I ran into a problem
recently when I try to write a GUI.
The thing is I want to periodically update the content of StatixText
object, so after create them, I pack them into a list...the problem
comes when I later try to extract them from the list! I don't know
why?
my code is as following:
import wx, socket
import thread
class MyFrame(wx.Frame):
firstrun = 0
def __init__(self):
wx.Frame.__init__(self, None, -1, 'Notifier')
self.panel = wx.Panel(self, -1)
self.length = 50
self.scale = 0.6
self.count = 5
self.size = wx.Frame.GetSize(self)
self.distance = self.size[1] / self.count
self.labellist = []
self.gaugelist = []
def ParseAndDisplay(self, data):
print Successful access to main Frame class
print 'And receive data: ', data
if MyFrame.firstrun == 0:
print 'First time run'
items = 3
for i in range(items):
self.labellist.append(wx.StaticText(self.panel, -1, data+str(i),
(150, 50+i*20), (300,30)))
MyFrame.firstrun = 1
else:
self.labellist[0].SetLabel('AAA')//PROGRAM WILL ABORT HERE!!!
self.labellist[1].SetLabel(Guo)
self.labellist[2].SetLabel(Qiang)
class NetUdp:
def __init__(self):
self.port = 8081
self.s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
self.s.bind((, self.port))
print Listening on port, self.port
def recvdata(self):
data, addr = self.s.recvfrom(1024)
return data
def netThread():
netudp = NetUdp()
while True:
data = netudp.recvdata()
frame.ParseAndDisplay(data)
if __name__ == '__main__':
firstrun = 0
app = wx.PySimpleApp()
frame = MyFrame()
frame.Show()
# start network thread first
id = thread.start_new_thread(netThread, ())
# main wxpython loop begins
app.MainLoop()
I know the code is ugly, but can anyone really save me here!
Communication OS thread - wx has to be done in a certain way. You must not
do this directly, i.e. you must not call wx code from w/i an OS thread. See
the wxPython Demo for an example of what you want to do: Process and
Events - Threads.
Cheers
Thin
--
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Re: Generating a unique identifier
On Fri, 07 Sep 2007 12:03:23 +, Steven D'Aprano wrote: I have an application that will be producing many instances, using them for a while, then tossing them away, and I want each one to have a unique identifier that won't be re-used for the lifetime of the Python session. I can't use the id() of the object, because that is only guaranteed to be unique during the lifetime of the object. For my application, it doesn't matter if the ids are predictable, so I could do something as simple as this: def unique_id(): n = 1234567890 while True: yield n n += 1 unique_id = unique_id() while Application_Is_Running: make_an_object(id=unique_id()) do_stuff_with_objects() delete_some_of_them() which is easy enough, but I thought I'd check if there was an existing solution in the standard library that I missed. For that easy solution you can use `itertools.count()`. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
application version checking against database
We are trying to implement a system that checks the version of the application against a version number stored in the database. We don't want the app and the db don't become out of sync. We have tried setting a __version__ variable in the top most module, however, it seems that this is not accessible for the modules that are subsequently imported. There are a several locations in the app where we want to do the version check, but we would like to have one place to set the version number, namely the top level module. We have thought of creating a Version class and passing it around, but aren't really keen on that idea. Any suggestions/ideas would be helpful. NOTE: the app is developed in wxPython. g. -- http://mail.python.org/mailman/listinfo/python-list
Re: unexpected behavior: did i create a pointer?
Am Fri, 07 Sep 2007 10:40:47 + schrieb Steven D'Aprano: Python doesn't have any pointers. Thinking of python variables or names as pointers should get you a long way when trying to understand python's behaviour. As long as you keep in mind that python doesn't have pointers to pointers, and no pointer arithmetic either... Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Class design (information hiding)
Alexander Eisenhuth schrieb: I'm wodering how the information hiding in python is ment. As I understand there doesn't exist public / protected / private mechanism, but a '_' and '__' naming convention. As I figured out there is only public and private possible as speakin in C++ manner. Are you all happy with it. What does the zen of python say to that design? (protected is useless?) My favourite thread to this FAQ: http://groups.google.at/group/comp.lang.python/browse_thread/thread/2c85d6412d9e99a4/b977ed1312e10b21#b977ed1312e10b21 Greg -- http://mail.python.org/mailman/listinfo/python-list
Re: py2exe - change name of exe created
Sorry for the double post, sent it to quickly.
I have a setup script like this;
setup(windows = [{script:myprogram.py,
icon_resources:[(0,nabbitt.ico)],
other_resources: [(24,1,manifest)]}
],
name = My Program ver 0.1,
data_files = [(,rootdata)],
zipfile = None,
options = {py2exe: {
compressed : 1,
dll_excludes:
[w9xpopen.exe],
bundle_files: 3
}
},
)
Note that every thing works fine with this and creates an exe program
called
myprogram.exe
I would like to setup program to create an output called;
MyBestProgram.exe
IS that at all possible ?
Geoff.
--
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py2exe - change name of exe created
I have a setup script like this;
setup(windows = [{script:myprogram.py,
icon_resources:[(0,nabbitt.ico)],
other_resources: [(24,1,manifest)]}
],
name = Nabbitt ver 0.1,
data_files = [(,rootdata)],
zipfile = None,
options = {py2exe: {
compressed : 1,
dll_excludes:
[w9xpopen.exe], #should also exclude
MSVCR71.dll
bundle_files: 3 #
1=Single .exe, 2=.exe with
pythonXX.dll
}
},
)
--
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Re: interesting puzzle......try this you will be rewarded...
On Sep 7, 5:08 am, Andreas Tawn [EMAIL PROTECTED] wrote: Maybe http://www.pythonchallenge.com/? That's the one, thanks! --- -- http://mail.python.org/mailman/listinfo/python-list
Re: Class design (information hiding)
Alexander Eisenhuth a écrit : Hi all, I'm wodering how the information hiding in python is ment. Conventions... As I understand there doesn't exist public / protected / private mechanism, but a '_' and '__' naming convention. Yes. As I figured out there is only public and private possible as speakin in C++ manner. Nope. It's either 'interface' (no leading underscore), 'implementation' (single leading underscore), 'implementation with some protection against accidental overriding' (two leading underscores). Are you all happy with it. Can't speak for others, but as far as I'm concerned, I'm perfectly happy with this. class A: def __init__(self): self.__z = 1 self._z = 2 self.z = 3 def _getX(self): return X def __getY(self): return Y def doAnything(self): print self.__getY() class B(A): def __init__(self): A.__init__(self) print dir (self) b = B() ['_A__getY', '_A__z', '__doc__', '__init__', '__module__', '_getX', '_z', 'doAnything', 'z'] I was a bit surprised about '_A__getY' and '_A__z'. It's documented. (snip) What is the idea behind the _ and __ naming. cf above. You may also want to read this - while C++ is not Java either, some advises may still apply: http://dirtsimple.org/2004/12/python-is-not-java.html HTH -- http://mail.python.org/mailman/listinfo/python-list
Re: unexpected behavior: did i create a pointer?
On Fri, 07 Sep 2007 11:46:38 +0200, Wildemar Wildenburger wrote: gu wrote: hi to all! after two days debugging my code, i've come to the point that the problem was caused by an unexpected behaviour of python. or by lack of some information about the program, of course! i've stripped down the code to reproduce the problem: [snip FAQ] Yes, basically you *created* a pointer. That's all that python has: pointers. No, you are confusing the underlying C implementation with Python. Python doesn't have any pointers. CPython is implemented with pointers. PyPy, being written entirely in Python, is implemented with Python objects like lists and dicts. Jython, being implemented in Java, probably isn't implemented with pointers either -- although of course the underlying Java compiler might be. IronPython and Python for .Net, I have no idea how they work. Could be magic for all I know. (Probably necromancy.) Naturally, regardless of whether you are using CPython, IronPython, PyPy or some other variety of Python, the objects available to you include ints, floats, strings, lists, dicts, sets and classes... but not pointers. Nor does it include peek and poke commands for reading and writing into random memory locations. Python is not C, and it is not Basic, nor is it Forth or Lisp or assembler, and you shouldn't hammer the round peg of Python objects into the square hole of C pointers. -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
Re: why should I learn python
On 07/09/07, Tom Brown [EMAIL PROTECTED] wrote: On Thursday 06 September 2007 16:01, windandwaves wrote: Hmmm, thank you all for your replies. I will do some research on the net (i did some already, but because I am really not much of a programmer, it is often too detailed for me). I have limited time, but it does sound like something to learn, just for fun and for practical use. How would you use it in a web development environment? I mean, in real practical terms. Could it assist with php? Is it easy to write GUI programs in Python? Checkout http://www.djangoproject.com/ or http://turbogears.org/ for web development. Checkout http://www.riverbankcomputing.co.uk/pyqt/index.php for writing GUI programs. There are other options for GUI apps. That is the one I use all the time. Also, check out Karrigell ( www.karrigell.com) . It will show you just how easy fast Python can be for web development. It has its own web server, or it can sit behind Apache etc. HTH :) -- http://mail.python.org/mailman/listinfo/python-list
Re: Checking if elements are empty
On Fri, 07 Sep 2007 11:12:05 +0200, Wildemar Wildenburger wrote: Lawrence D'Oliveiro wrote: In message [EMAIL PROTECTED], Chris Mellon wrote: On 9/5/07, Steve Holden [EMAIL PROTECTED] wrote: Doran, Harold wrote: Is there a way to check if the first element of y is null? len(y[0]) == 0 Better spelled as if y[0]: Not a good idea. Why not? What happens if y is an empty list? -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
Re: Using s.sort([cmp[, key[, reverse]]]) to sort a list of objects based on a attribute
[EMAIL PROTECTED] writes: Hi there I am fairly new to Python and have not really used regular expressions before (I think this might be needed for my query) and wondered if you could help I have a step class and store in a list step instances A step instance contains variables: name, startTime etc and startTime is stored as a string %H:%M:%S What I would like to do is to be able to sort this list of objects based on the startTime object so that the first item in the list is the object with the earliest Start time and last item is the object with the last Start time. I belive my key has to be = strpTime(step.sTime, %H:%M:%S) But don't know how to create the comparison funciton. Any help on how I can perform this whole operation would be much appreciated. Code: class Step(object): def __init__(self, time): self.time = time def __repr__(self): return Step time=%s % self.time steps = [Step(03:23:23), Step(12:59:12), Step(02:32:17)] print steps steps.sort(key = lambda s: s.time) print steps Output: [Step time=03:23:23, Step time=12:59:12, Step time=02:32:17] [Step time=02:32:17, Step time=03:23:23, Step time=12:59:12] If the default sort order of a Step is always it's time then you can also define a __cmp__ method like this: class Step(object): def __cmp__(self, other): return cmp(self.time, other.time) And simply do a steps.sort() S. -- http://mail.python.org/mailman/listinfo/python-list
Re: py2exe - change name of exe created
imageguy schrieb:
Sorry for the double post, sent it to quickly.
I have a setup script like this;
setup(windows = [{script:myprogram.py,
icon_resources:[(0,nabbitt.ico)],
other_resources: [(24,1,manifest)]}
],
name = My Program ver 0.1,
data_files = [(,rootdata)],
zipfile = None,
options = {py2exe: {
compressed : 1,
dll_excludes:
[w9xpopen.exe],
bundle_files: 3
}
},
)
Note that every thing works fine with this and creates an exe program
called
myprogram.exe
I would like to setup program to create an output called;
MyBestProgram.exe
IS that at all possible ?
Yes. Use a 'dest_base' key in the dictionary, like so:
setup(windows = [{script:myprogram.py,
icon_resources:[(0,nabbitt.ico)],
dest_base: MyBestProgram,
other_resources: [(24,1,manifest)]}
...
'dest_base' is the basename of the destination program that py2exe creates.
Thomas
--
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Re: Using s.sort([cmp[, key[, reverse]]]) to sort a list of objects based on a attribute
[EMAIL PROTECTED] wrote: Hi there I am fairly new to Python and have not really used regular expressions before (I think this might be needed for my query) and wondered if you could help I have a step class and store in a list step instances A step instance contains variables: name, startTime etc and startTime is stored as a string %H:%M:%S What I would like to do is to be able to sort this list of objects based on the startTime object so that the first item in the list is the object with the earliest Start time and last item is the object with the last Start time. I belive my key has to be = strpTime(step.sTime, %H:%M:%S) But don't know how to create the comparison funciton. You're going to get a *lot* of answers on this one! To start the ball rolling... code import random class Step: def __init__ (self, name, startTime): self.name = name self.startTime = startTime def __cmp__ (self, other): return cmp (self.startTime, other.startTime) def __str__ (self): return str (self.startTime) __repr__ = __str__ steps = [Step (h, %02d:00:00 % h) for h in range (10)] random.shuffle (steps) print Shuffled:, steps steps.sort () print Sorted:, steps /code In this case, I've given the class a ordering-semantic based on its startTime attribute. Obviously, this only makes sense if you *always* want your class to sort this way, rather than in this one instance. To do it on a per-sort basis, you *could* create simple per-sort equivalent: code fragment def compare_by_startTime (one, other): return cmp (one.startTime, other.startTime) steps.sort (cmp=compare_by_startTime) /code or, in the case you're asking about, you could use the operator module's attrgetter function to do what you want: code fragment import operator steps.sort (key=operator.attrgetter (startTime)) /code TJG -- http://mail.python.org/mailman/listinfo/python-list
Re: Generating a unique identifier
On Sep 7, 7:03 am, Steven D'Aprano [EMAIL PROTECTED] cybersource.com.au wrote: I have an application that will be producing many instances, using them for a while, then tossing them away, and I want each one to have a unique identifier that won't be re-used for the lifetime of the Python session. I can't use the id() of the object, because that is only guaranteed to be unique during the lifetime of the object. For my application, it doesn't matter if the ids are predictable, so I could do something as simple as this: def unique_id(): n = 1234567890 while True: yield n n += 1 unique_id = unique_id() while Application_Is_Running: make_an_object(id=unique_id()) do_stuff_with_objects() delete_some_of_them() which is easy enough, but I thought I'd check if there was an existing solution in the standard library that I missed. Also, for other applications, I might want them to be rather less predictable. -- Steven. You could always use the md5 module along with time.time() to generate a unique id. Mike -- http://mail.python.org/mailman/listinfo/python-list
Is a Borg rebellion possible? (a metaclass question)
In my application, I make use of the Borg idiom, invented by Alex
Martelli.
class Borg(object):
'''Borg Idiom, from the Python Cookbook, 2nd Edition, p:273
Derive a class form this; all instances of that class will share
the
same state, provided that they don't override __new__; otherwise,
remember to use Borg.__new__ within the overriden class.
'''
_shared_state = {}
def __new__(cls, *a, **k):
obj = object.__new__(cls, *a, **k)
obj.__dict__ = cls._shared_state
return obj
This has worked very well so far, but is starting to impose some
unwanted constraints on my program design.
What I would like to do is, to put it figuratively, create a Borg
rebellion with various splinter groups. In concrete Python terms, I
would like to have
class MyClass(Borg, ...):
...
seven_of_nine = MyClass(...) # part of group BORG
two_of_nine = MyClass(...)
splinter1 = MyClass(..., group='splinter')
splinter2 = MyClass(..., group='splinter')
and have splinter 1 and splinter2 share the same state, but a
different state than the one shared by members of the BORG collective.
Any suggestions from the metaclass experts?
André
--
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Re: Generating a unique identifier
On Fri, Sep 07, 2007 at 12:03:23PM -, Steven D'Aprano wrote: [...] which is easy enough, but I thought I'd check if there was an existing solution in the standard library that I missed. Also, for other applications, I might want them to be rather less predictable. 2.5 includes the uuid module for RFC 4122 universally-unique IDs: http://docs.python.org/lib/module-uuid.html -- [Will [EMAIL PROTECTED]|http://www.lfod.us/] -- http://mail.python.org/mailman/listinfo/python-list
Generating a unique identifier
I have an application that will be producing many instances, using them for a while, then tossing them away, and I want each one to have a unique identifier that won't be re-used for the lifetime of the Python session. I can't use the id() of the object, because that is only guaranteed to be unique during the lifetime of the object. For my application, it doesn't matter if the ids are predictable, so I could do something as simple as this: def unique_id(): n = 1234567890 while True: yield n n += 1 unique_id = unique_id() while Application_Is_Running: make_an_object(id=unique_id()) do_stuff_with_objects() delete_some_of_them() which is easy enough, but I thought I'd check if there was an existing solution in the standard library that I missed. Also, for other applications, I might want them to be rather less predictable. -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
Re: Best practice prompting for password
On 9/7/07, GiBo [EMAIL PROTECTED] wrote: Hi, what's the best practice to securely prompt user for password on console in Python? IIRC some programs like SSH do a lot to ensure that the input comes from TTY and is not redirected from somewhere and several other checks. In the case of OpenSSH even the password prompt is always displayed regardless if the output is redirected to a file or not. Any pointers to best practice or code snippet of python password prompt? The getpass module. -- http://mail.python.org/mailman/listinfo/python-list
Re: MySQLdb: ValueError Something Stupid
On 7 Sep, 14:11, Carsten Haese [EMAIL PROTECTED] wrote:
On Fri, 2007-09-07 at 05:52 -0700, mcl wrote:
ValueError: invalid literal for int(): 0-
args = ('invalid literal for int(): 0-',)
=
Thanks Richard
Sort of solved it.
On that particular table it did not like * for all fields.
Any reason why that would be the case ?
None that we can divine without more information. What's the schema for
the table in question, which column(s) are you excluding to make the
query work, and what kind of data is in the column(s) you're excluding?
--
Carsten Haesehttp://informixdb.sourceforge.net
Thanks for replying.
I did not exclude any columns and the Schema is:
CREATE TABLE lstData (
qlCat varchar(20) NOT NULL default '',
qlTitle varchar(255) NOT NULL default '',
qlSubTitle varchar(255) default NULL,
qlDetails text,
qlPic varchar(20) default NULL,
qlPostCode varchar(16) default NULL,
qlUpd timestamp NOT NULL default '-00-00 00:00:00' on update
CURRENT_TIMESTAMP,
KEY `idx-qlCat` (qlCat)
) ENGINE=MyISAM DEFAULT CHARSET=latin1;
Thanks again
Richard
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Re: MySQLdb: ValueError Something Stupid
On 7 Sep, 12:08, mcl [EMAIL PROTECTED] wrote:
I have just started with python and MySQL.
I have a simple test for each of my tables.
The first two work as expected, but the third 'qlooks', gives a
ValueError.
If I copy and paste the SQL in the traceback to phpMyAdmin, it works
as expected.
Can anyone give a clue as to what I am doing wrong
Python 2.4
MySQL 4.1.22-standard
The tablename qlooks is LOWERCASE
Code ===
cursor = gv.conn.cursor()
queries = [%septi%]
fields = (qlTitle, qlSubTitle, qlPostCode, qlMap,
qlDetails)
tblFields = select * from qlooks
whereTests = 'Where qlTitle like %septi%'
sql = tblFields + whereTests
#cursor.execute(sql)
cursor.execute('select * from PERMS')
row = cursor.fetchone()
print Row=, row, gv.nl
cursor.execute('select * from LISTS')
row = cursor.fetchone()
print Row=, row, gv.nl
cursor.execute('select * from qlooks')
row = cursor.fetchone()
print Row=, row, gv.nl
cursor.close()
ERROR TRACEBACK
79 print Row=, row, gv.nl
80 cursor.execute('select * from qlooks')
81 row = cursor.fetchone()
82 print Row=, row, gv.nl
cursor = MySQLdb.cursors.Cursor instance, cursor.execute = bound
method Cursor.execute of MySQLdb.cursors.Cursor instance
/usr/lib/python2.4/site-packages/MySQLdb/cursors.py in
execute(self=MySQLdb.cursors.Cursor instance, query='select * from
qlooks', args=None)
93
94 del self.messages[:]
95 return self._execute(query, args)
96
97 def _execute(self, query, args):
self = MySQLdb.cursors.Cursor instance, self._execute = bound
method Cursor._execute of MySQLdb.cursors.Cursor instance, query =
'select * from qlooks', args = None
/usr/lib/python2.4/site-packages/MySQLdb/cursors.py in
_execute(self=MySQLdb.cursors.Cursor instance, query='select * from
qlooks', args=None)
112 exc, value, tb = exc_info()
113 del tb
114 self.errorhandler(self, exc, value)
115 self._executed = query
116 return r
self = MySQLdb.cursors.Cursor instance, self.errorhandler = bound
method Connection.defaulterrorhandler of ...l.connection open to
'db.sabren.com' at 936cac4, exc = class exceptions.ValueError,
value = exceptions.ValueError instance
/usr/lib/python2.4/site-packages/MySQLdb/connections.py in
defaulterrorhandler(connection=_mysql.connection open to
'db.sabren.com' at 936cac4, cursor=MySQLdb.cursors.Cursor instance,
errorclass=class exceptions.ValueError,
errorvalue=exceptions.ValueError instance)
31 else:
32 connection.messages.append(error)
33 raise errorclass, errorvalue
34
35
errorclass = class exceptions.ValueError, errorvalue =
exceptions.ValueError instance
ValueError: invalid literal for int(): 0-
args = ('invalid literal for int(): 0-',)
=
Thanks Richard
Sort of solved it.
On that particular table it did not like * for all fields.
Any reason why that would be the case ?
Richard
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Re: exponential float formmating
On Sep 7, 6:08 am, [EMAIL PROTECTED] wrote: Hi, For compatibility reasons with an old program I have to format string in exponential format with the following format 0.xE-yy This means that the number start always by 0 and after the exponent there should be alway the sing and 2 number for the exponent. for example 13 shoud be 0.13000E+02 I always get 1.3E001 Perhaps it would then be worthwhile to subclass float? import math class ffloat(float): Formatted float? def __str__(self): prefix = (self 0) and '-' or '' fabs = math.fabs(self) exponent = math.floor(math.log10(fabs)) + 1 significand = fabs / math.pow(10, exponent) width = exponent 0 and 2 or 3 return '%s%fE%0*d' % (prefix,significand,width,exponent) f = ffloat(13) print f f = ffloat(-12.23e-4) print f -- Hope this helps, Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: interesting puzzle......try this you will be rewarded...
Basilisk96 wrote: I remember seeing a more elaborate puzzle that involved coding, cryptography knowledge, etc. to get through it. But what was the link, I forget now... There's this one http://www.inwardhellix.net/ I haven't played it yet so I can't vouch for its quality. (am playing it now) Maybe http://www.pythonchallenge.com/ ? Cheers, Drea Andreas Tawn Lead Technical Artist Ubisoft Reflections -- http://mail.python.org/mailman/listinfo/python-list
Re: platform system may be Windows or Microsoft since Vista
Log a bug @ bugs.python.org
http://bugs.python.org/issue1082
TITLE ... platform system may be Windows or Microsoft since Vista
Six days gone with no feedback. Something wrong with the input?
Maybe the blank Priority field?
I agree Severity Major.
I'm thinking no priority because there is no fixing this. We now
choose between two wrong ways to change the Python Msi installer of
Windows:
1. Hide that many people now and for months or years to come will
continue to need both halves of the (platform.system() in ('Windows',
'Microsoft') guard.
2. Leave unchanged to require many more people to need both halves in
future.
I find neither choice inspiring.
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Re: exponential float formmating
On 7 sep, 15:42, Marc 'BlackJack' Rintsch [EMAIL PROTECTED] wrote:
On Fri, 07 Sep 2007 06:08:19 -0700, zunbeltz wrote:
For compatibility reasons with an old program I have to format string
in exponential format with the following format
0.xE-yy
This means that the number start always by 0 and after the exponent
there should be alway the sing and 2 number for the exponent.
for example 13 shoud be 0.13000E+02
I always get 1.3E001
I don't know if this is platform dependent but this works for me:
In [41]: '%e' % 1.3
Out[41]: '1.30e+00'
In [42]: ('%e' % 1.3).upper()
Out[42]: '1.30E+00'
Ciao,
Marc 'BlackJack' Rintsch
I am working in windows I get
'%e' % 13
'1.30e+001'
In all cases I need the number to start with 0
0.13000E+01
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Re: Generating a unique identifier
Will Maier wrote: On Fri, Sep 07, 2007 at 12:03:23PM -, Steven D'Aprano wrote: [...] which is easy enough, but I thought I'd check if there was an existing solution in the standard library that I missed. Also, for other applications, I might want them to be rather less predictable. 2.5 includes the uuid module for RFC 4122 universally-unique IDs: http://docs.python.org/lib/module-uuid.html Jesus Christ! What in all the world *doesn't* Python do already?! Can't we now just write up a module for the standard lib that takes care of writing all the other code as well and just forget about getting our hands dirty with programming altogether? /W (just in case: ;)!) -- http://mail.python.org/mailman/listinfo/python-list
re: getting the current function
This all seems a bit too complicated. Are you sure you want to do this? Maybe you need to step back and rethink your problem. In version 2.1 Python added the ability to add function attributes -- see http://www.python.org/dev/peps/pep-0232/ for the justifications. A counter probably isn't one of them, I just used that as a quick example of using thisfunc(). I've just never liked the fact that you have to name the function when accessing those attributes from within the function. And I thought there might be other uses for something like thisfunc(). -- Gary Robinson CTO Emergent Music, LLC [EMAIL PROTECTED] 207-942-3463 Company: http://www.goombah.com Blog:http://www.garyrobinson.net -- http://mail.python.org/mailman/listinfo/python-list
Re: why should I learn python
In a message dated 2007-9-7 7:50:32, [EMAIL PROTECTED] writes: Tom Brown wrote: On Thursday 06 September 2007 15:44, Torsten Bronger wrote: Hallöchen! Tom Brown writes: [...] Python has been by far the easiest to develop in. Some people might say it is not real programming because it is so easy. I can't believe this. Have you really heard such a statement? Yes. I was told this by a C programmer. Something about doing it all yourself and not using provided packages. I countered with something about reinventing the wheel. :) Point this so-called C Programmer toward Henry Spencer's Ten Commandments of C Programming. Note in particular rule 7: 7. Thou shalt study thy libraries and strive not to reinvent them without cause, that thy code may be short and readable and thy days pleasant and productive. You can find the whole list here: http://www.everything2.com/index.pl?node_id=783755 -- _http://mail.python.org/mailman/listinfo/python-list_ (http://mail.python.org/mailman/listinfo/python-list) [EMAIL PROTECTED] (mailto:[EMAIL PROTECTED]) ? This seems like Bill Gates' email,does he also like Python? :-) ** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour -- http://mail.python.org/mailman/listinfo/python-list
Re: How to determine the bool between the strings and ints?
Jorgen Bodde a écrit : Hi All, I have a dictionary with settings. The settinfgs can be strings, ints or bools. I would like to write this list dynamically to disk in a big for loop, unfortunately the bools need to be written as 0 or 1 to the config with WriteInt, the integers also with WriteInt and the strings with a simple Write. The list is something like; options[A] = True options[B] = 1 options[C] = Hello I wanted to use isinstance to determine if it is a bool or an int or a string. However I am confused trying it out in the interactive editor; a = False if isinstance(a, bool): ... print OK ... OK if isinstance(a, int): ... print OK ... OK I don't get it. is the bool derived from 'int' in some way? Obviously : yes !-) What is the best way to check if the config I want to write is an int or a bool ? isinstance(0, bool) False isinstance(1, bool) False But anyway, I don't get the point, since the bools need to be written as 0 or 1 to the config with WriteInt, the integers also with WriteInt. So you just don't care if it's a bool or not ? Or did I miss something ? -- http://mail.python.org/mailman/listinfo/python-list
Re: Generating a unique identifier
Paul Rubin http://[EMAIL PROTECTED] writes:
def unique_id():
return os.urandom(10).encode('hex')
Sorry, make that 32 or 40 instead of 10, if the number of id's is large,
to make birthday collisions unlikely.
If you don't want the id's to be that large, you can implement a
Feistel cipher using md5 or sha as the round function pretty
straightforwardly, then just feed successive integers through it.
That also guarantees uniqueness, at least within one run of the
program. I have some sample code around for that, let me know if you
need it.
--
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Re: Organizing Code - Packages
xkenneth a écrit : All, I apologize if this is a commonly asked question, but I didn't find anything that answered my question while searching. So what I have right now is a few packages that contain some commonly used functions and another package that contains all of my custom error classes. I want these error classes available to me in all of the other packages in my library. Currently to achieve this at the top of every module file I have the line from My.Library.Errors import *, my problem with this is that it manages to import the Errors into every scope that they are used. Ain't that what you want ??? Having these error classes available to me in all of the other packages in my library ? If you're worried about perfs or whatever, don't worry, a module is only imported once - next imports will only bind the names in the importing namespace. I'm still pretty new to Python, and my approachs are probably very rooted in C/C++ (I've had the hardest time getting over not being able to overload functions), but am I doing this correctly? Yes, that's the right thing to do. Also, are there any good tutorials/examples out there of how to organize your python code into packges? Most of the Python-specific aspects should be covered by the tutorial (the one in the doc). Else, it's as usual, trying to have high cohesion and low coupling. Ah, yes, a couple of things: - avoid the 'one-class-per-file' syndrom. It's perfectly ok to have tens of classes in a same module - plain functions are ok too - no need to stick everything in classes. HTH -- http://mail.python.org/mailman/listinfo/python-list
Organizing Code - Packages
All, I apologize if this is a commonly asked question, but I didn't find anything that answered my question while searching. So what I have right now is a few packages that contain some commonly used functions and another package that contains all of my custom error classes. I want these error classes available to me in all of the other packages in my library. Currently to achieve this at the top of every module file I have the line from My.Library.Errors import *, my problem with this is that it manages to import the Errors into every scope that they are used. I'm still pretty new to Python, and my approachs are probably very rooted in C/C++ (I've had the hardest time getting over not being able to overload functions), but am I doing this correctly? Also, are there any good tutorials/examples out there of how to organize your python code into packges? Thanks for all the help! Regards, Ken -- http://mail.python.org/mailman/listinfo/python-list
How to determine the bool between the strings and ints?
Hi All, I have a dictionary with settings. The settinfgs can be strings, ints or bools. I would like to write this list dynamically to disk in a big for loop, unfortunately the bools need to be written as 0 or 1 to the config with WriteInt, the integers also with WriteInt and the strings with a simple Write. The list is something like; options[A] = True options[B] = 1 options[C] = Hello I wanted to use isinstance to determine if it is a bool or an int or a string. However I am confused trying it out in the interactive editor; a = False if isinstance(a, bool): ... print OK ... OK if isinstance(a, int): ... print OK ... OK I don't get it. is the bool derived from 'int' in some way? What is the best way to check if the config I want to write is an int or a bool ? Regards, - Jorgen -- http://mail.python.org/mailman/listinfo/python-list
Re: Class design (information hiding)
Alexander Eisenhuth a écrit : Bruno Desthuilliers schrieb: Nope. It's either 'interface' (no leading underscore), 'implementation' (single leading underscore), 'implementation with some protection against accidental overriding' (two leading underscores). What do you mean with 'implementation'? What does it express? The fact that a given attribute (or method - which are just callable attributes FWIW) is an implementation detail, and not a part of the class interface. -- http://mail.python.org/mailman/listinfo/python-list
Re: How to determine the bool between the strings and ints?
Awesome! Thanks you! As for why caring if they are bools or not, I write True and False to the properties, the internal mechanism works like this so I need to make that distinction. Thanks again guys, - Jorgen ps. Sorry TheFlyingDutch for mailing you personally, I keep forgetting this mailinglist does not default back to the user list when replying ;-) -- http://mail.python.org/mailman/listinfo/python-list
Re: concise code (beginner)
On Sep 6, 1:56 pm, Karthik Gurusamy [EMAIL PROTECTED] wrote: That said, it may be a good future language enhancement to define a reasonable consistent behavior for an iterator over a changing collection. This occurs quite common when we walk a collection and usually delete the current item. For a sequence, what the expected behavior is quite obvious (just remove this element and go over to the next). For other collections like dictionary/set, again if the operation is delete, the expected behavior is obvious. If we are doing insertion, for sequence a well- defined behavior can be formulated (based on insert before or after current position -- if after we will see it in the walk, if before we won't see it) . For dict/set I see this isn't simple (as based on hash key we may insert ahead or later of the current 'cursor'/position. Removing from a list while you iterate will had quadratic performance though. O(n) to find the element you wish to remove and move over everything after it, multiplied by your original O(n) of iterating, gives O(n**2). That, combined with the fact that adding enough accounting to invalidate or update your iterator would be a cost on all the correct users too, is why it's not done. The best approach in almost all cases in python is to create a new container as you iterate over the old one. After you finish, you replace the old one with the new one. This lets you keep an overall O(n) performance, as well as avoiding the tricky semantics. -- Adam Olsen, aka Rhamphoryncus -- http://mail.python.org/mailman/listinfo/python-list
Using s.sort([cmp[, key[, reverse]]]) to sort a list of objects based on a attribute
Hi there I am fairly new to Python and have not really used regular expressions before (I think this might be needed for my query) and wondered if you could help I have a step class and store in a list step instances A step instance contains variables: name, startTime etc and startTime is stored as a string %H:%M:%S What I would like to do is to be able to sort this list of objects based on the startTime object so that the first item in the list is the object with the earliest Start time and last item is the object with the last Start time. I belive my key has to be = strpTime(step.sTime, %H:%M:%S) But don't know how to create the comparison funciton. Any help on how I can perform this whole operation would be much appreciated. Thanks Chris -- http://mail.python.org/mailman/listinfo/python-list
Re: why should I learn python
Why use Python? 1)Easy to read, debug and think. 2)Same language for batch scripting, server programming and dynamic web page creation. 3)Libraries like wxPython for desktop and Cherrypy for web development. 4)Pythonic JavaScript Library Mochikit. 5)Engineered for reality, not corporate proprietary control (Microsoft). 6)Less code than Java the Huge. 7)Friendly with C for optimization, if necessary. 8)Works well with SQL, especially PostgreSQL. 9)Everybody is using it, even Microsoft with IronPython. 10)One of the dominant languages driving robotics. 11)Works nicely with UNICODE. 12)Liberal license. 13)And lastly, if you hate programming as I do, you will love Python. Belief is when someone else does the thinking. ~ Buckminster Fuller -- http://mail.python.org/mailman/listinfo/python-list
Re: Is a Borg rebellion possible? (a metaclass question)
On Fri, 2007-09-07 at 12:31 +, André wrote:
In my application, I make use of the Borg idiom, invented by Alex
Martelli.
class Borg(object):
'''Borg Idiom, from the Python Cookbook, 2nd Edition, p:273
Derive a class form this; all instances of that class will share
the
same state, provided that they don't override __new__; otherwise,
remember to use Borg.__new__ within the overriden class.
'''
_shared_state = {}
def __new__(cls, *a, **k):
obj = object.__new__(cls, *a, **k)
obj.__dict__ = cls._shared_state
return obj
This has worked very well so far, but is starting to impose some
unwanted constraints on my program design.
What I would like to do is, to put it figuratively, create a Borg
rebellion with various splinter groups. In concrete Python terms, I
would like to have
class MyClass(Borg, ...):
...
seven_of_nine = MyClass(...) # part of group BORG
two_of_nine = MyClass(...)
splinter1 = MyClass(..., group='splinter')
splinter2 = MyClass(..., group='splinter')
and have splinter 1 and splinter2 share the same state, but a
different state than the one shared by members of the BORG collective.
Any suggestions from the metaclass experts?
You don't need a metaclass. Just turn _shared_state into a dictionary of
shared states, keyed by the group name:
class SplinterBorg(object):
_shared_states = {}
def __new__(cls, *a, **k):
group = k.pop(group,BORG)
obj = object.__new__(cls, *a, **k)
obj.__dict__ = cls._shared_states.setdefault(group,{})
return obj
HTH,
--
Carsten Haese
http://informixdb.sourceforge.net
--
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exponential float formmating
Hi, For compatibility reasons with an old program I have to format string in exponential format with the following format 0.xE-yy This means that the number start always by 0 and after the exponent there should be alway the sing and 2 number for the exponent. for example 13 shoud be 0.13000E+02 I always get 1.3E001 Thanks, Zunbeltz -- http://mail.python.org/mailman/listinfo/python-list
Re: py2exe - change name of exe created
On Sep 7, 11:22 am, Thomas Heller [EMAIL PROTECTED] wrote:
imageguy schrieb:
Sorry for the double post, sent it to quickly.
I have a setup script like this;
setup(windows = [{script:myprogram.py,
icon_resources:[(0,nabbitt.ico)],
other_resources: [(24,1,manifest)]}
],
name = My Program ver 0.1,
data_files = [(,rootdata)],
zipfile = None,
options = {py2exe: {
compressed : 1,
dll_excludes:
[w9xpopen.exe],
bundle_files: 3
}
},
)
Note that every thing works fine with this and creates an exe program
called
myprogram.exe
I would like to setup program to create an output called;
MyBestProgram.exe
IS that at all possible ?
Yes. Use a 'dest_base' key in the dictionary, like so:
setup(windows = [{script:myprogram.py,
icon_resources:[(0,nabbitt.ico)],
dest_base: MyBestProgram,
other_resources: [(24,1,manifest)]}
...
'dest_base' is the basename of the destination program that py2exe creates.
Thomas- Hide quoted text -
- Show quoted text -
Thanks.
I really appreciate the response.
Where would I find that in the docs ? Thought I had searched
everywhere.
G.
--
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Re: Is a Borg rebellion possible? (a metaclass question)
On Sep 7, 10:27 am, Carsten Haese [EMAIL PROTECTED] wrote:
On Fri, 2007-09-07 at 12:31 +, André wrote:
In my application, I make use of the Borg idiom, invented by Alex
Martelli.
class Borg(object):
'''Borg Idiom, from the Python Cookbook, 2nd Edition, p:273
Derive a class form this; all instances of that class will share
the
same state, provided that they don't override __new__; otherwise,
remember to use Borg.__new__ within the overriden class.
'''
_shared_state = {}
def __new__(cls, *a, **k):
obj = object.__new__(cls, *a, **k)
obj.__dict__ = cls._shared_state
return obj
This has worked very well so far, but is starting to impose some
unwanted constraints on my program design.
What I would like to do is, to put it figuratively, create a Borg
rebellion with various splinter groups. In concrete Python terms, I
would like to have
class MyClass(Borg, ...):
...
seven_of_nine = MyClass(...) # part of group BORG
two_of_nine = MyClass(...)
splinter1 = MyClass(..., group='splinter')
splinter2 = MyClass(..., group='splinter')
and have splinter 1 and splinter2 share the same state, but a
different state than the one shared by members of the BORG collective.
Any suggestions from the metaclass experts?
You don't need a metaclass. Just turn _shared_state into a dictionary of
shared states, keyed by the group name:
class SplinterBorg(object):
_shared_states = {}
def __new__(cls, *a, **k):
group = k.pop(group,BORG)
obj = object.__new__(cls, *a, **k)
obj.__dict__ = cls._shared_states.setdefault(group,{})
return obj
HTH,
--
Carsten Haesehttp://informixdb.sourceforge.net
Unfortunately, it fails. Here's what I tried, followed by the
traceback
class SplinterBorg(object):
_shared_states = {}
def __new__(cls, *a, **k):
group = k.pop(group,BORG)
obj = object.__new__(cls, *a, **k)
obj.__dict__ = cls._shared_states.setdefault(group,{})
return obj
class MyClass(SplinterBorg):
def __init__(self, name):
self.name = name
a1 = MyClass('a')
a2 = MyClass('aa')
b1 = MyClass('b', group=B)
Traceback (most recent call last):
File test.py, line 15, in module
b1 = MyClass('b', group=B)
TypeError: __init__() got an unexpected keyword argument 'group'
--
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Re: interesting puzzle......try this you will be rewarded...
Andreas Tawn wrote: Maybe http://www.pythonchallenge.com/ ? Fun! Thanks! -- http://mail.python.org/mailman/listinfo/python-list
Re: unexpected behavior: did i create a pointer?
On Sep 7, 3:07 am, gu [EMAIL PROTECTED] wrote:
hi to all!
Hi!
after two days debugging my code, i've come to the point that the
problem was caused by an unexpected behaviour of python. or by lack of
some information about the program, of course! i've stripped down the
code to reproduce the problem:
code
a = {}
for x in range(10):
for y in range(10):
a[x,y] = 0
copyOfA = a
def functionA(x,y):
print a[x,y],
copyOfA[x,y] = *
print a[x,y],copyOfA[x,y]
for x in range(10):
for y in range(10):
functionA(x,y)
/code
now, in the second for cycle and in functionA() i only 'touch' copyOfA
(altering it). as i don't touch the variable a, i expect it not to be
affected by any change, but copyOfA acts like a pointer to a and
altering copyOfA's values result in altering the values of a, so the
result that i expect is:
0 0 *
0 0 *
0 0 *
0 0 *
[..]
but i get:
0 * *
0 * *
0 * *
0 * *
[..]
what's going on?
thanks in advance.
Welcome to Python! You might want to look at the documentation:
http://docs.python.org/
And the tutorials:
http://docs.python.org/tut/tut.html
Leaping into python from another language without looking at the above
documentation is not wise, since python has both a very different
structure and a somewhat different philosophy from other languages.
--
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debugging program that uses ctypes
hi all, I have a python program that calls a dll through ctypes (py2.5). In some (reproducible) conditions the program crashes with an error in ctypes module. How can I trace down the problem? I have created a debug build of python but I also use pyodbc and dateutil libraries in my program and I don't know how to make them visible to python_d.exe Am I using the right approach? thanks in advance for hints, Marco -- http://mail.python.org/mailman/listinfo/python-list
Re: Generating a unique identifier
Steven D'Aprano [EMAIL PROTECTED] writes:
def unique_id():
n = 1234567890
while True:
yield n
n += 1
unique_id = itertools.count(1234567890)
which is easy enough, but I thought I'd check if there was an existing
solution in the standard library that I missed. Also, for other
applications, I might want them to be rather less predictable.
def unique_id():
return os.urandom(10).encode('hex')
--
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Re: Speed of Python
On Sep 7, 6:42 pm, wang frank [EMAIL PROTECTED] wrote: Matlab (aka MATrix LABoratory) has been designed with numeric computations in mind (every object being natively a n-dim array). If you wish to develop that kind of applications in Python, consider using the numerical array structure provided by Numpy. Numpy being mostly written in C, that should speed up your application ... In this context, additional 3rd party libs such as Scipy, Matplotlib, PIL, etc. will also be useful. Cheers, SB Hi, While comparing the speed of octave and matlab, I decided to do a similar test for python and matlab. The result shows that python is slower than matlab by a factor of 5. It is not bad since octave is about 30 time slower than matlab. Here is the result in matlab: Elapsed time is 0.015389 seconds. and in Python: t=timeit.Timer(bench1.bench1(10),import bench1) t.repeat(1,1) [0.071012377266015392] Here is the bench1.py: import math def bench1(n): for i in range(n): for j in range(1000): m=j+1 z=math.log(m) z1=math.log(m+1) z2=math.log(m+2) z3=math.log(m+3) z4=math.log(m+4) z5=math.log(m+5) z6=math.log(m+6) z7=math.log(m+7) z8=math.log(m+8) z9=math.log(m+9) return z9 Is my conclusion correct that Python is slower than matlab? Are there any way to speed it up? It seems Python automatically created bench1.pyc. Does Python automatically execute the bench1.pyc to speed it up? Thanks Frank _ 「地図マガ」特集 残暑を吹きとばせ！ご当地アイスクリームマップが登場http://chizumaga.jp/ -- http://mail.python.org/mailman/listinfo/python-list
passing command line arguments
Hi, when I run the script show_args2.py # ./show_args2.py 1 2 3 I get the following error Traceback (most recent call last): File ./show_args2.py, line 4, in ? print 'The arguments of %s are %s' %s \ NameError: name 's' is not defined # mailto:[EMAIL PROTECTED] this is the script #!/usr/bin/python import sys, string print 'The arguments of %s are %s' %s \ (sys.argv[0], string.join(sys.argv[1:])) any help would be greatly appreciated -Brian -- http://mail.python.org/mailman/listinfo/python-list
Re: Organizing Code - Packages
xkenneth [EMAIL PROTECTED] writes: Ah, yes, a couple of things: - avoid the 'one-class-per-file' syndrom. It's perfectly ok to have tens Yes but i find it hard to edit classes easily when I have more than one class per file. Why? -- http://mail.python.org/mailman/listinfo/python-list
Re: debugging program that uses ctypes
[EMAIL PROTECTED] schrieb: hi all, I have a python program that calls a dll through ctypes (py2.5). In some (reproducible) conditions the program crashes with an error in ctypes module. You mean a segfault? How can I trace down the problem? I have created a debug build of python but I also use pyodbc and dateutil libraries in my program and I don't know how to make them visible to python_d.exe Am I using the right approach? I would say yes. It seems you are using windows - running debug builds of python on windows start a dialog box that allows to attach the MSVC debugger to the running program. Usually this allows to locate the error fairly quickly. As you have discovered, the problem is that you need to build all the extensions that you use in debug mode otherwise you cannot use them. If you cannot rebuild the extensions you have to reproduce the crash in a script that doesn't use these extensions. Thomas -- http://mail.python.org/mailman/listinfo/python-list
Re: Organizing Code - Packages
Ah, yes, a couple of things: - avoid the 'one-class-per-file' syndrom. It's perfectly ok to have tens Yes but i find it hard to edit classes easily when I have more than one class per file. Regards, Ken -- http://mail.python.org/mailman/listinfo/python-list
Re: How to convert None to null value
En Fri, 07 Sep 2007 06:19:25 -0300, pradeep kumar [EMAIL PROTECTED]
escribi�:
i am trying to insert records from one table to another table in postgres
sql using the the following code
posConn.query(insert into
usr(usr_id,usr_name,usr_passwd,grp_cde,usr_type,usr_chk_till_val, \
usr_active,usr_daily_auth,usr_lst_login,usr_lst_logout,usr_shift_id,usr_role_level)
values \
('%s','%s','%s',%s,%i,%d,'%s',%i,%i,%i,%i,%i)
%(row[0],row[1],row[2],row[3],row[4],row[5], \
row[7],row[8],row[10],row[11],row[12],row[14]) )
here row[4] column is having null value so python consides it as None but
will insert into the table it inserts as None not null value
- You are building the sql statement by hand: don't do that. The query
method receives two arguments: an sql template with placeholders, and a
tuple of arguments. This way, None objects are correctly translated into
NULL values, embedded quotes are correctly handled, etc. An important
point is security - building the sql statement by hand may open the door
to sql injection attacks.
See http://www.python.org/dev/peps/pep-0249/ for details.
- You don't need those \ for line continuation: any expression containing
an open ( [ { automatically continues on the following lines until all ) ]
} are closed.
- Python automatically joins contiguous strings.
Combining all the above:
posConn.query(insert into usr
(usr_id,usr_name,usr_passwd,grp_cde,usr_type,
usr_chk_till_val,usr_active,usr_daily_auth,
usr_lst_login,usr_lst_logout,usr_shift_id,
usr_role_level) values
(%s,%s,%s,%s,%i,%d,%s,%i,%i,%i,%i,%i) ,
(row[0],row[1],row[2],row[3],row[4],row[5],
row[7],row[8],row[10],row[11],row[12],row[14]))
Note the TWO arguments to the query method: all those string fragments are
joined into a single string, followed by a comma, and a tuple containing 6
parameters.
Parameter markers may be %s,%s,%s... as above, or :1,:2,:3... or ?,?,?...
The exact syntax depends on your specific database adapter - you'll have
to read its documentation.
--
Gabriel Genellina
--
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Re: why should I learn python
On Sep 6, 10:32 pm, windandwaves [EMAIL PROTECTED] wrote: Can someone tell me why I should learn python? I am a webdeveloper, but I often see Python mentioned and I am curious to find out what I am missing out on. Thank you Nicolaas - You never really have to reinvent the wheel, and many python modules are included by default. This means that you can accomplish what you wanted to do much faster. Thus You can write a lot less code to get to what you want to do. If a module does not exist yet, you can create it! - It is kinda close to pseudo code, so you can 'think' much easier in python. - It can be used for many many tasks, and you can adapt your application as need be. - It is still quite fast and lightweight! - The community in general is quite helpful - It is quite fun to use - If it's good enough for nasa.. :-P In regards to people claiming it is not 'real', that is a load of poo! Ignore thy c elitists. Eric Raymond wrote a nice 'Why Python?' article. http://www.linuxjournal.com/article/3882 -- http://mail.python.org/mailman/listinfo/python-list
Re: Class design (information hiding)
On 9/7/07, Alexander Eisenhuth [EMAIL PROTECTED] wrote: Hi all, I'm wodering how the information hiding in python is ment. As I understand there doesn't exist public / protected / private mechanism, but a '_' and '__' naming convention. As I figured out there is only public and private possible as speakin in C++ manner. Are you all happy with it. What does the zen of python say to that design? (protected is useless?) Strictly speaking, everything is public in python. Members prefixed with __ just get name mangled. But conceptually, yes, there is only public and private members. Information hiding is based on convention, otherwise it would be hard to write debuggers in python, which by definition wants to break the information hiding principle. If you're not writing a debugger, doc generator, or other type of meta level program, follow the conventions of not peeking under the hood. class A: def __init__(self): self.__z = 1 self._z = 2 self.z = 3 def _getX(self): return X def __getY(self): return Y def doAnything(self): print self.__getY() class B(A): def __init__(self): A.__init__(self) print dir (self) b = B() ['_A__getY', '_A__z', '__doc__', '__init__', '__module__', '_getX', '_z', 'doAnything', 'z'] I was a bit surprised about '_A__getY' and '_A__z'. This is so that in class B, you can also have members called __getY and __z, and they won't interfere with class A (they'll be called _B__getY and _B__z respectively ). What would you say to a C++ Programmer about class interfaces in big Python systems? What is the idea behind the _ and __ naming. As a rough analogy: __name - private _name - protected Use or don't use '_' methods ? (As Designer of the software, as Programmer of the software) I don't know if you're making a distinction here between designer and programmer. Are you meaning implementer of library and user of library? As a user of a library, never ever explicitly call members starting with an underscore. Regards Alexander -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: Speed of Python
On Sep 7, 12:42 pm, wang frank [EMAIL PROTECTED] wrote: Here is the bench1.py: import math def bench1(n): for i in range(n): for j in range(1000): m=j+1 z=math.log(m) z1=math.log(m+1) z2=math.log(m+2) z3=math.log(m+3) z4=math.log(m+4) z5=math.log(m+5) z6=math.log(m+6) z7=math.log(m+7) z8=math.log(m+8) z9=math.log(m+9) return z9 Is my conclusion correct that Python is slower than matlab? Show us your Matlab code in order to see if both are equivalent. Your Python code creates n lists of 1000 elements, so you're not actually measuring only the numeric computations. Cheers, -- Roberto Bonvallet -- http://mail.python.org/mailman/listinfo/python-list
Re: Changing data in an QAbstractListModel
On Sep 7, 12:42 am, Jonathan Gardner [EMAIL PROTECTED] wrote: On Sep 6, 9:12 am, exhuma.twn [EMAIL PROTECTED] wrote: I defined a simple update method in the model which I call on certain events to fetch the new data in the DB. I tried to emit the dataChanged() signal of the Model without success. I don't know where I should get the two required index parameters from. Any hints? Shouldn't the index method give you the indexes you need? Right... The update method now looks like this: def update(self): c = db_con.cursor() # SELECT only the most recent entry for each company c.execute(SELECT DISTINCT ON (unit_id) nom FROM unit ORDER BY unit_id, year DESC) for unit in c.fetchall(): self.__units.append( unit[0] ) c.close() si = self.index(0) se = self.index(len(self.__units)-1) self.emit(Signal(dataChanged()), si, se) Still, nothing is happening when I call this method. Do I still need to handle the dataChanged signal somehow? Or does the ListView take care of this? -- http://mail.python.org/mailman/listinfo/python-list
MySQL: Global Connection
It is tough when the grey matter is getting past it. I am starting to use MySQL and I would like to make my connection to my database a variable in my Global Variable Class, but I just can not see how to do it. Class GlobalVars : -- http://mail.python.org/mailman/listinfo/python-list
Re: Why 'class spam(object)' instead of class spam(Object)' ?
On Fri, 07 Sep 2007 01:30:00 -0500, Sergio Correia wrote: Hi, I'm kinda new to Python (that means, I'm a total noob here), but have one doubt which is more about consistency that anything else. Why if PEP 8 says that Almost without exception, class names use the CapWords convention, does the most basic class, object, is lowercase? It said almost. :) I found a thread about this: http://mail.python.org/pipermail/python-list/2007-April/437365.html where its stated that -object- is actually a type, not a class; but the idea still doesn't convince me. There's a false dichotomy there: it's not an either-or situation. Almost everyone would agree that new-style classes, defined by the Python class statement, are both classes and types. Some might squabble over whether object is class, but it has nothing to do with why object is spelled in lower-case. The reason why object is lower case is because built-in types are spelled in lower-case. Why are built-in types lower case? Because many built-in types were originially functions. For example, int and str were once functions. When these symbols became the names of their respective types, they kept the lower-case spelling, and it became convention for built-in types to be spelled lower-case. Carl Banks -- http://mail.python.org/mailman/listinfo/python-list
wxPython unexpected exit
Hi, wxPython is cool and easy to use, But I ran into a problem
recently when I try to write a GUI.
The thing is I want to periodically update the content of StatixText
object, so after create them, I pack them into a list...the problem
comes when I later try to extract them from the list! I don't know
why?
my code is as following:
import wx, socket
import thread
class MyFrame(wx.Frame):
firstrun = 0
def __init__(self):
wx.Frame.__init__(self, None, -1, 'Notifier')
self.panel = wx.Panel(self, -1)
self.length = 50
self.scale = 0.6
self.count = 5
self.size = wx.Frame.GetSize(self)
self.distance = self.size[1] / self.count
self.labellist = []
self.gaugelist = []
def ParseAndDisplay(self, data):
print Successful access to main Frame class
print 'And receive data: ', data
if MyFrame.firstrun == 0:
print 'First time run'
items = 3
for i in range(items):
self.labellist.append(wx.StaticText(self.panel,
-1, data+str(i),
(150, 50+i*20), (300,30)))
MyFrame.firstrun = 1
else:
self.labellist[0].SetLabel('AAA')//PROGRAM WILL ABORT
HERE!!!
self.labellist[1].SetLabel(Guo)
self.labellist[2].SetLabel(Qiang)
class NetUdp:
def __init__(self):
self.port = 8081
self.s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
self.s.bind((, self.port))
print Listening on port, self.port
def recvdata(self):
data, addr = self.s.recvfrom(1024)
return data
def netThread():
netudp = NetUdp()
while True:
data = netudp.recvdata()
frame.ParseAndDisplay(data)
if __name__ == '__main__':
firstrun = 0
app = wx.PySimpleApp()
frame = MyFrame()
frame.Show()
# start network thread first
id = thread.start_new_thread(netThread, ())
# main wxpython loop begins
app.MainLoop()
I know the code is ugly, but can anyone really save me here!
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unexpected behavior: did i create a pointer?
hi to all!
after two days debugging my code, i've come to the point that the
problem was caused by an unexpected behaviour of python. or by lack of
some information about the program, of course! i've stripped down the
code to reproduce the problem:
code
a = {}
for x in range(10):
for y in range(10):
a[x,y] = 0
copyOfA = a
def functionA(x,y):
print a[x,y],
copyOfA[x,y] = *
print a[x,y],copyOfA[x,y]
for x in range(10):
for y in range(10):
functionA(x,y)
/code
now, in the second for cycle and in functionA() i only 'touch' copyOfA
(altering it). as i don't touch the variable a, i expect it not to be
affected by any change, but copyOfA acts like a pointer to a and
altering copyOfA's values result in altering the values of a, so the
result that i expect is:
0 0 *
0 0 *
0 0 *
0 0 *
[..]
but i get:
0 * *
0 * *
0 * *
0 * *
[..]
what's going on?
thanks in advance.
--
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Python and Cron
This may be more of a Linux question, but I'm hoping some of you may be able to help me. I have a python (2.4) routine running on Gentoo Linux. It creates a file and, after the file is complete, renames the file using the os.rename() command. When I run the file from the command line everything works great, but when I schedule the job to run from the crontab file, the original file is created and populated, but the rename fails. I am using full paths for both the original and destination file, and run the command line version after I 'su' to the production account (named 'edith'). I am told by my sysadmin that the cron jobs run as edith as well, so he does not think it is a permission issue (he points out the original file is being created and populated as expected...the rename fails) Have any of you dealt with anything like this? It really has me scratching my head. Thanks, --greg -- http://mail.python.org/mailman/listinfo/python-list
Re: Why 'class spam(object)' instead of class spam(Object)' ?
Sergio Correia a écrit : Hi, I'm kinda new to Python (that means, I'm a total noob here), but have one doubt which is more about consistency that anything else. Why if PEP 8 says that Almost without exception, class names use the CapWords convention, does the most basic class, object, is lowercase? Because it is an exception ?-) Notice that all builtin types (list, dict, set, str, unicode, int, long, float, tuple, file, object, type, function, classmethod, staticmethod, property etc) are lower-case. (snip interrogations about object's type) class Eggs(object): def __init__(self): self.x = 1 type(Eggs) type 'type' Type 'type'? What is that supposed to mean? type(Eggs) is roughly equivalent to Eggs.__class__, ie it returns the class of the Eggs class object, IOW the metaclass. In Python, classes are objects, so they are themselves instances of a class - by default, for new-style classes, instances of the class 'type'. In case you wonder, class 'type' is an instance of itself. Hope this makes any sense ;), Idem !-) -- http://mail.python.org/mailman/listinfo/python-list
Re: interesting puzzle......try this you will be rewarded...
On 2007-09-07, Gabriel Genellina [EMAIL PROTECTED] wrote: En Thu, 06 Sep 2007 22:57:21 -0300, Basilisk96 [EMAIL PROTECTED] escribi?: I got to 14 :) It's rather silly. I remember seeing a more elaborate puzzle that involved coding, cryptography knowledge, etc. to get through it. But what was the link, I forget now... Me too, and I can't find that link either. #15 is a bit difficult for people outside US, and spelling on #21 is questionable, but I liked this woody thing :) Y'all may be thinking of The Euler Project, which provides math puzzles for programmers. http://projecteuler.net/ -- Neil Cerutti I pulled away from the side of the road, glanced at my mother-in-law and headed over the embankment. --Insurance Claim Blooper -- http://mail.python.org/mailman/listinfo/python-list
Re: startswith( prefix[, start[, end]]) Query
TheFlyingDutchman wrote: Else, you could as well write your own testing function: def str_starts_with(astring, *prefixes): startswith = astring.startswith for prefix in prefixes: if startswith(prefix): return true return false What is the reason for startswith = astring.startswith startswith(prefix) instead of astring.startswith(prefix) It's an optimization: the assigment creates a bound method (i.e. a method associated with a specific string instance) and avoids having to look up the startswith method of astring for each iteration of the inner loop. Probably not really necessary, though, and they do say that premature optimization is the root of all evil ... regards Steve -- Steve Holden+1 571 484 6266 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://del.icio.us/steve.holden --- Asciimercial -- Get on the web: Blog, lens and tag the Internet Many services currently offer free registration --- Thank You for Reading - -- http://mail.python.org/mailman/listinfo/python-list
Re: unexpected behavior: did i create a pointer?
Steven D'Aprano wrote: On Fri, 07 Sep 2007 11:46:38 +0200, Wildemar Wildenburger wrote: gu wrote: hi to all! after two days debugging my code, i've come to the point that the problem was caused by an unexpected behaviour of python. or by lack of some information about the program, of course! i've stripped down the code to reproduce the problem: [snip FAQ] Yes, basically you *created* a pointer. That's all that python has: pointers. No, you are confusing the underlying C implementation with Python. I do not, as I have no clue of the C implementation :). I just thought I'd go along with the analogy the OP created as that was his mindset and it would make things easier to follow if I didn't try to forcibly change that. Please note that I had intended for the word 'created' to be in quotes rather than asterisks. I bit myself after I read my mistake online but then thought Who cares?. I should have, maybe :). And yes, I will admit that going along with that analogy isn't the best way to explain it. Grant Edwards in reply to Peter Otten makes it much clearer, I guess. /W -- http://mail.python.org/mailman/listinfo/python-list
Why 'class spam(object)' instead of class spam(Object)' ?
Hi, I'm kinda new to Python (that means, I'm a total noob here), but have one doubt which is more about consistency that anything else. Why if PEP 8 says that Almost without exception, class names use the CapWords convention, does the most basic class, object, is lowercase? I found a thread about this: http://mail.python.org/pipermail/python-list/2007-April/437365.html where its stated that -object- is actually a type, not a class; but the idea still doesn't convince me. If i create a class Spam using -object- as a parent class, I would expect -object- to be a class, not a type as in type(object) (what is the difference between both btw?). But, on the other hand, if I do help(object), I get: help(object) Help on class object in module __builtin__: class object | The most base type So is this a class? No... object type 'object' My doubts get compounded when strange stuff starts to happen: class Eggs(object): def __init__(self): self.x = 1 type(Eggs) type 'type' Type 'type'? What is that supposed to mean? Hope this makes any sense ;), Sergio -- http://mail.python.org/mailman/listinfo/python-list
Re: library to launch program in linux
On 2007-09-07, Lawrence D'Oliveiro [EMAIL PROTECTED] wrote: In message [EMAIL PROTECTED], Laszlo Nagy wrote: Grant Edwards wrote: On 2007-09-06, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: I'm a new user. What library should I use so that I can launch program in linux using python? subprocess Hmm, there are some others... subprocess subsumes them all. And someday soon, subprocess will RULE THE WORLD! BWA-HAHAHAHAH! -- Neil Cerutti -- http://mail.python.org/mailman/listinfo/python-list
py2exe - change name of exe created
I have a setup script like this;
setup(windows = [{script:myprogram.py,
icon_resources:[(0,nabbitt.ico)],
other_resources: [(24,1,manifest)]}
],
name = Nabbitt ver 0.1,
data_files = [(,rootdata)],
zipfile = None,
options = {py2exe: {
compressed : 1,
dll_excludes:
[w9xpopen.exe], #should also exclude
MSVCR71.dll
bundle_files: 3 #
1=Single .exe, 2=.exe with
pythonXX.dll
}
},
)
--
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Re: Text processing and file creation
On Sep 7, 3:50 am, George Sakkis [EMAIL PROTECTED] wrote: On Sep 5, 5:17 pm, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: If this was a code golf challenge, I'd choose the Unix split solution and be both maintainable as well as concise :-) - Paddy. -- http://mail.python.org/mailman/listinfo/python-list
Re: concise code (beginner)
On Sep 6, 7:44 am, bambam [EMAIL PROTECTED] wrote: First, thank you. All of the suggestions match what we want to do much better than what we are doing. We have a script, written in python, which is doing testing. But the python script doesn't look anything like the test script, because the python script is written in python, and the test script is a series of instrument command macros. By putting the script sequence into a collection that is separate from the python code, we will get script list that general engineering will find much easier to understand: def script(self) def a0010(): global self; self.power_on([self.dev]); def a0020(): global self; self.dev.addLog([self.name, ' started']); def a0030(): global self; self.resetMinuteReg([self.dev]); def a0040(): global self; self.disablePLmessages([self.dev]); def a0050(): global self; self.dev.testH.writePLram((PL.BCAL128)); Look at generative tests in py.test or nose: they are a much better solution for what you are doing. Michele Simionato -- http://mail.python.org/mailman/listinfo/python-list
Python wrapper, problem with subprocess read/write
Hello, I am writing a wrapper to a basic Input/Output programs (where you type a one line command at a time and then get 0 or more lines of output before you can input the next command). I'm sorry if this problem description is a bit long, but I wanted to make the problem clear. Example run of the original program: C:\home\start Starting up program [Welcome to program v.X.Y.Z] blahblahblah and some more lines input command program response... more program response... etc. another command ... This is what the wrapper is expected to do... 1: Start up the program. 2: Forward the startup printouts by the program until the line where it first asks for a command. 3: When waiting for input, input a command from a sequential list of strings (or other source of strings). 4: Forward the programs printouts until all lines are read and the program prompts for new command. 5: Repeat 3-4 until list is depleted or program is terminated and then close the program. Now, to the problem: In step 2/4, how to read all lines except the one which is unfinished (in the example, the lines beginning with ) and waiting for input? My attempts use something like this: proc = Popen(['programname'], stdout = PIPE, stdin = PIPE ) for string_element in string_source : proc.stdin.write(string_element) lines = proc.stdout.readlines() method_that_processes_output(lines) The problem with this is that stdout.readlines() doesn't return since it reads until EOF... I tried instead to use: lines = [] line = proc.stdout.readline() while line : lines.append(line) line = proc.stdout.readline() This prints out everything except the line, which is good. But then freezes while waiting for input, which is bad. Any suggestions on how to solve this in a good way? -- http://mail.python.org/mailman/listinfo/python-list
Speed of Python
Hi, While comparing the speed of octave and matlab, I decided to do a similar test for python and matlab. The result shows that python is slower than matlab by a factor of 5. It is not bad since octave is about 30 time slower than matlab. Here is the result in matlab: Elapsed time is 0.015389 seconds. and in Python: t=timeit.Timer(bench1.bench1(10),import bench1) t.repeat(1,1) [0.071012377266015392] Here is the bench1.py: import math def bench1(n): for i in range(n): for j in range(1000): m=j+1 z=math.log(m) z1=math.log(m+1) z2=math.log(m+2) z3=math.log(m+3) z4=math.log(m+4) z5=math.log(m+5) z6=math.log(m+6) z7=math.log(m+7) z8=math.log(m+8) z9=math.log(m+9) return z9 Is my conclusion correct that Python is slower than matlab? Are there any way to speed it up? It seems Python automatically created bench1.pyc. Does Python automatically execute the bench1.pyc to speed it up? Thanks Frank _ 「地図マガ」特集 残暑を吹きとばせ！ご当地アイスクリームマップが登場 http://chizumaga.jp/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Why 'class spam(object)' instead of class spam(Object)' ?
Carl Banks wrote: On Fri, 07 Sep 2007 01:30:00 -0500, Sergio Correia wrote: Hi, I'm kinda new to Python (that means, I'm a total noob here), but have one doubt which is more about consistency that anything else. Why if PEP 8 says that Almost without exception, class names use the CapWords convention, does the most basic class, object, is lowercase? It said almost. :) Indeed it did, and never forget that most of PEP 8 was derived from an essay by Guido whose original title was A Foolish Consistency is the Hobgoblin of Little Minds ... I found a thread about this: http://mail.python.org/pipermail/python-list/2007-April/437365.html where its stated that -object- is actually a type, not a class; but the idea still doesn't convince me. You don't have to be convinced. You just have to do what the PEP says yourself and ignore the people who *haven't* done what it says (particularly if they are core Python developers). There's a false dichotomy there: it's not an either-or situation. Almost everyone would agree that new-style classes, defined by the Python class statement, are both classes and types. Some might squabble over whether object is class, but it has nothing to do with why object is spelled in lower-case. The reason why object is lower case is because built-in types are spelled in lower-case. Why are built-in types lower case? Because many built-in types were originially functions. For example, int and str were once functions. When these symbols became the names of their respective types, they kept the lower-case spelling, and it became convention for built-in types to be spelled lower-case. In other words: Get over it ;-) regards Steve -- Steve Holden+1 571 484 6266 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://del.icio.us/steve.holden --- Asciimercial -- Get on the web: Blog, lens and tag the Internet Many services currently offer free registration --- Thank You for Reading - -- http://mail.python.org/mailman/listinfo/python-list
Re: startswith( prefix[, start[, end]]) Query
Bruno Desthuilliers wrote: Steve Holden a écrit : [...] Probably not really necessary, though, and they do say that premature optimization is the root of all evil ... I wouldn't call this one premature optimization, since it doesn't change the algorithm, doesn't introduce (much) complication, and is proven to really save on lookup time. Now I do agree that unless you have quite a lot of prefixes to test, it might not be that necessary in this particular case... The defense rests. regards Steve -- Steve Holden+1 571 484 6266 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://del.icio.us/steve.holden --- Asciimercial -- Get on the web: Blog, lens and tag the Internet Many services currently offer free registration --- Thank You for Reading - -- http://mail.python.org/mailman/listinfo/python-list
Class design (information hiding)
Hi all, I'm wodering how the information hiding in python is ment. As I understand there doesn't exist public / protected / private mechanism, but a '_' and '__' naming convention. As I figured out there is only public and private possible as speakin in C++ manner. Are you all happy with it. What does the zen of python say to that design? (protected is useless?) class A: def __init__(self): self.__z = 1 self._z = 2 self.z = 3 def _getX(self): return X def __getY(self): return Y def doAnything(self): print self.__getY() class B(A): def __init__(self): A.__init__(self) print dir (self) b = B() ['_A__getY', '_A__z', '__doc__', '__init__', '__module__', '_getX', '_z', 'doAnything', 'z'] I was a bit surprised about '_A__getY' and '_A__z'. What would you say to a C++ Programmer about class interfaces in big Python systems? What is the idea behind the _ and __ naming. Use or don't use '_' methods ? (As Designer of the software, as Programmer of the software) Regards Alexander -- http://mail.python.org/mailman/listinfo/python-list
