ANN: easygconf 0.02
I'm happy to announce easygconf 0.02.
Get it at http://www.florian-diesch.de/software/easygconf
easygconf provids an easy, pythonic way to access GConf
through a dict-like interface.
Example
---
from easygconf import GConfDict
import gtk
key = 'test
gc=GConfDict('/apps/easygconftest')
print %s is %s%(key, gc[key])
gc[key] = 'foo'
print Now %s is %s%(key, gc[key])
def callback (key, value, gconfdict, id, args):
print %s changed to %s%(key, value)
gc.add_listner('test', callback)
try:
gtk.main()
except KeyboardInterrupt:
pass
gc.unset('test')
Florian
--
http://www.florian-diesch.de/
--
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Support the Python Software Foundation:
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Elixir 0.7.1 released
I am very pleased to announce that version 0.7.1 of Elixir (http://elixir.ematia.de) is now available. As always, feedback is very welcome, preferably on Elixir mailing list. This release packs a few interesting new features (abstract classes and a new collection type providing explicit relative resolution of target entities) and some bug fixes. It is a safe upgrade from the 0.7.0 release. The full list of changes can be seen at: http://elixir.ematia.de/trac/browser/elixir/tags/0.7.1/CHANGES What is Elixir? - Elixir is a declarative layer on top of the SQLAlchemy library. It is a fairly thin wrapper, which provides the ability to create simple Python classes that map directly to relational database tables (this pattern is often referred to as the Active Record design pattern), providing many of the benefits of traditional databases without losing the convenience of Python objects. Elixir does not intend to replace SQLAlchemy's core features, and instead focuses on providing a simpler syntax for defining model objects when you do not need the full expressiveness of SQLAlchemy's manual mapper definitions. Mailing list http://groups.google.com/group/sqlelixir/about -- Gaëtan de Menten http://openhex.org -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations/
Re: python simply not scaleable enough for google?
On 14 Nov, 02:42, Robert Brown bbr...@speakeasy.net wrote: If you want to know why Python *the language* is slow, look at the Lisp code CLPython generates and at the code implementing the run time. Simple operations end up being very expensive. You can also see this by looking at the C that Cython or Pyrex generates. You can also see the dramatic effect by a handful of strategically placed type declarations. -- http://mail.python.org/mailman/listinfo/python-list
The ol' [[]] * 500 bug...
...just bit me in the fuzzy posterior. The best I can come up with is the hideous lol = [[] for _ in xrange(500)] Is there something better? What did one do before comprehensions were available? I suppose in that case one would have to go all the way with lol = [None] * 500 for i in xrange(len(lol)): lol[i] = [] Yikes. 10 miles uphill, both ways... kynn -- http://mail.python.org/mailman/listinfo/python-list
Re: The ol' [[]] * 500 bug...
In 6e20a31b-2218-49c5-a32c-5f0147db3...@k19g2000yqc.googlegroups.com Jon Clements jon...@googlemail.com writes: lol =3D map(lambda L: [], xrange(5)) [id(i) for i in lol] [167614956, 167605004, 167738060, 167737996, 167613036] Oh yeah, map! I'd forgotten all about it. Thanks! kynn -- http://mail.python.org/mailman/listinfo/python-list
Re: A terminators' club for clp
In 7x3a4i56u7@ruckus.brouhaha.com Paul Rubin http://phr...@nospam.invalid writes: kj no.em...@please.post writes: frequent* clp posters the ability to *easily* delete spam from the comp.lang.python server? Um, this is usenet; there is no comp.lang.python server. Are you saying you want a moderated newsgroup? Hmm, maybe this group is busy enough that there is some merit to that idea. Sorry, I had a mistaken view of how usenet was implemented. But yeah, I guess I'm thinking of a moderated newsgroup, but with a large number of moderators working in parallel, and a very lax acceptance policy. The goal is to filter out only the obvious spam, and let through all the other non-spam traffic as quickly as possible... What do I mean by obvious spam? Well, among the most recent messages (that have survived my killfile policies) I see the following subject lines: * Top 10 US mp3 songs.Cheers * www.find68.com cheaper nike shoes g-satr kidrobot hoodies ed hardy star red monkey gino green global true religion ed-hardy kidrobot jeans hoodies china supplier wholesaler exporters,manufacture * jobs in france jobs in france for english people jobs in france for foreigners jobs in france for australians jobs in france for foreigners jobs in france for new zealanders jobs paris jobs http://jobs-in-fr ance.blogspot.com/ * germany jobs germany job sites germany job search jobs in germany german jobs germany jobs it germany jobs for foreigners germany jobsite germany jobs in english on http://jobs-germany.blogspot.com/ Those look pretty obvious to me. But, as I already showed, I'm out of my depth here, so I'd better shut up. kynn -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Go
Simon Forman wrote: On Sat, Nov 14, 2009 at 5:10 PM, Terry Reedy tjre...@udel.edu wrote: Paul Rubin wrote: Mark Chu-Carroll has a new post about Go: http://scienceblogs.com/goodmath/2009/11/the_go_i_forgot_concurrency_an.php In a couple of minutes, I wrote his toy prime filter example in Python, mostly from the text rather than the code, which I can barely stand to read. It ran the first time without error. def plurals(): i = 2 while True: yield i i += 1 def primefilter(src, prime): for i in src: if i % prime: yield i src = plurals() while True: i = next(src) print(i) src = primefilter(src, i) As I commented there It stopped at 7877 when it hit the default recursion limit of 1000, which could easily be increased to get out-of-memory error instead. I think Google is making a blunder if it moves to another old-fashioned language whose code is bloated with junky boilerplate that doubles the size. It would be much better, for instance, to tweak Python, which it has had great success with, to better run on multiple cores. Terry Jan Reedy FWIW, def plurals(): i = 3 while True: yield i i += 2 Of course, in fact, I thought of at the time def plurals(): i = 6 while True: yield i-1 yield i+1 i += 6 5,7, 11,13, 17,19, 23,(25-first miss), 29,31, (35-2nd miss),37, 41,43, 47,(49 erd)...Reduced the base cases by another 1/3. I *think* without measuring, that that compensates for the extra -1,+1. But I was implementing *Mark's* toy example, and first posted it on his blog, so I copied his naive version. Even better, to avoid extra -1, +1 def plurals(): yield 2 yield 3 i = 5 while True: yield i i += 2 yield i i += 4 Of course, testing with primes greater that square root(candidate) is wasteful, and recusion should be converted to iteration to avoid recursion limit. Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: IDE for python
On Nov 16, 5:09 am, sturlamolden sturlamol...@yahoo.no wrote: On 15 Nov, 18:09, Peng Yu pengyu...@gmail.com wrote: There had been some discussion on IDE. But I'm not sure what pros and cons of each choice. Current, I'm using vim and ctags. Could somebody give some advices on choosing the best IDE for me? There is a plug-in to develop (amd debug) Python using MS Visual Studio. It works with IronPython and CPython. There is the PyDev plug-in for Eclipse. There is Komodo from ActiveState. There is KDevelop in KDE4. Which is better? I don't know. My impression is that Python development does noe need an IDE like e.g. C++ development do. There is no build process, which takes the major advantage of the IDE away. I am fine with a editor like IDLE or Kate. I'd like to offer the group the anecdote of the great Resolver IDE migration. Developers at Resolver, where I work, choose their own IDE. Being developers, that meant every single person chose a different one. We had them all. Which turned out, slightly unexpectedly, to be just fine. We pair on all production code. So this meant we all spent a lot of time sitting at each other's desks. We soon all became pretty familiar with each other's environments - there's nothing like 8 hours a day of hands-on usage, coupled with sitting right next to a bone-fide expert to get you up to speed pretty quick. I even learned a little Emacs, holy cow! Occasionally, after seeing the details of how well some other IDE worked, developers would switch from one to another. Then, after about a year, a curious thing happened. One by one, in entirely independent decisions, almost all developers decided to migrate to either Emacs or Vi.* Each person decided that the fancy features of their IDE wasn't as useful to them as having a flexible, powerful and lightweight editor which can easily be scripted to provide whatever ad-hoc features they need. I regard this as an example of the way pairing spreads knowledge. * I say 'most developers' - there were two notable exceptions: Michael Foord, who's prodigious contributions are legend, who likes Wing, and Will Reade, our tame brainiac, responsible for the exceedingly clever 'IronClad' open-source project, who likes the uncomplicated simplicity of TextPad. As far as I can make out, TextPad has only two features, syntax highlighting and the ability to define a 'make' command, and a regex that is used to extract filenames and line-numbers from the resulting output of that make command. These are, it turns out, sufficient to transform a program that would otherwise simply be 'Notepad' into an entirely credible development environment. -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Go
sturlamolden wrote: On 14 Nov, 23:10, Terry Reedy tjre...@udel.edu wrote: It would be much better, for instance, to tweak Python, which it has had great success with, to better run on multiple cores. Python run well on multiple cores, you just have to use processes instead of threads. But not so trivially as to add one word to an existing function. Hence by tweak, I meant, as explained in another post, to add a keyword or just a decorator that will do what the go keyword does in go. -- http://mail.python.org/mailman/listinfo/python-list
C api question and determining PyObject type
Hello I have an a class defined as: class __object(object): pass Now, I call a C function that takes a PyObject* and checks its type: if (PyString_Check(obj)) ... if (PySequence_Check(obj)) Before doing the check, I print the passed object with PyObject_Str() and get: passed object: __main__.__object object at 0x040E4050 However, the C code returns true on the: if (PySequence_Check(obj)) Why? That is not a sequence? Please advise. -- Elias -- http://mail.python.org/mailman/listinfo/python-list
python gui builders
Good People I do not write stuff for humans, as it has been my job to remove humans from the loop. But I have to make a front end to a component database where everything was built in Python. I have looked at the Tk stuff that is built into Python - not acceptable. So looking at wxGlade, Boa Constructor, Python Card. Also looked at the frames/forms created with QtDesigner, which can be used by Python via pyuic. BlackAdder IDE seems to have this built-in, but am loathe to buy into another GUI tool for a single job. I have not been able to find a decent Python gui builder. The last time I did gui garbage was with Borland C++ Builder which was ok because I was only using win boxen for that project. This time I am using both Linux and Win. What Python gui builder is well supported, does not require me to learn another framework/library, and can crank out stuff for multiple platforms ? thanks much, me -- http://mail.python.org/mailman/listinfo/python-list
Re: IDE for python
On 16 Nov, 10:05, Jonathan Hartley tart...@tartley.com wrote: As far as I can make out, TextPad has only two features, syntax highlighting and the ability to define a 'make' command, and a regex that is used to extract filenames and line-numbers from the resulting output of that make command. These are, it turns out, sufficient to transform a program that would otherwise simply be 'Notepad' into an entirely credible development environment. When working with Java or C++ I like and IDE like KDevelop because it makes makefiles for me. And when debugging it is easier to insert break points graphically than use gdb from the terminal. But apart from that, I prefer a tiny editor like Kate (yes I know, call me a heretic for not using emacs). -- http://mail.python.org/mailman/listinfo/python-list
Re: overriding __getitem__ for a subclass of dict
On Nov 15, 2:52 pm, Steve Howell showel...@yahoo.com wrote: Does anybody have any links that points to the rationale for ignoring instance definitions of __getitem__ when new-style classes are involved? I assume it has something to do with performance or protecting us from our own mistakes? Not important enough to justify complexity of implementation. I doubt they would have left if out of new-style classes if it had been straightforward to implement (if for no other reason than to retain backwards compatibility), but it wasn't. The way attribute lookups work meant it would have required all kinds of double lookups and edge cases. Some regarded it as dubious to begin with. And it's easily worked around by simply having __getitem__ call another method, as you've seen. Given all this it made better sense to just leave it out of new-style classes. Unfortunately not all such decisions and justifications are collected in a tidy place. Carl Banks -- http://mail.python.org/mailman/listinfo/python-list
Re: python gui builders
On 16 Nov, 11:06, me not_h...@nowhere.com wrote: What Python gui builder is well supported, does not require me to learn another framework/library, and can crank out stuff for multiple platforms ? I use wxFormBuilder. The 3.1 beta can even create wxPython code, but it still has some minor issues (e.g. not always creating correct code due to missing self.). wxFormBuilder 3.0 can create XRC files, which work excellently with wxPython. The drawback is that you must bind event handlers manually, instead of having it done automatically (as you can with Python code generation in 3.1 beta). If you are fine with GPL, or can afford the commercial license, there is QtDesigner which works with PyQt. This is a fantastic cross- platform GUI tool, if not hte best there is. If you are fine with Microsoft only, you can use Windows Forms with MS Visual Studio and IronPython. If you can use Jython, there are many tools for working with Java Swing or SWT. -- http://mail.python.org/mailman/listinfo/python-list
Re: IDE for python
On Nov 16, 1:05 am, Jonathan Hartley tart...@tartley.com wrote: Then, after about a year, a curious thing happened. One by one, in entirely independent decisions, almost all developers decided to migrate to either Emacs or Vi.* Each person decided that the fancy features of their IDE wasn't as useful to them as having a flexible, powerful and lightweight editor which can easily be scripted to provide whatever ad-hoc features they need. I regard this as an example of the way pairing spreads knowledge. That's the best justification for pair programming I've seen yet. Carl Banks -- http://mail.python.org/mailman/listinfo/python-list
Re: python gui builders
On 16 Nov, 11:39, sturlamolden sturlamol...@yahoo.no wrote: If you are fine with Microsoft only, you can use Windows Forms with MS Visual Studio and IronPython. I also forgot to mention: If you can restrict yourself to Windows, you can always use Visual Basic or Borland Delphi with pywin32. Either expose your GUI as an ActiveX to pywin32 (you have e.g. an MFC binding) or expose your Python as an ActiveX to VB/Delphi. The same approach should work (with a little bit more work) for C# and VB.NET. -- http://mail.python.org/mailman/listinfo/python-list
Re: C api question and determining PyObject type
Actually, the object class is defined as:
class __object(object):
def __getitem__(self, idx):
return getattr(self, idx)
Anyway, now I check like this:
bool PyIsSequenceType(PyObject *obj)
{
if (!PySequence_Check(obj))
return false;
Py_ssize_t sz = PySequence_Size(obj);
if (sz == -1 || PyErr_Occurred() != NULL)
{
PyErr_Clear();
return false;
}
return true;
}
I don't like it, any other suggestions?
--
Elias
lallous lall...@lgwm.org wrote in message news:hdr80a$vs...@aioe.org...
Hello
I have an a class defined as:
class __object(object):
pass
Now, I call a C function that takes a PyObject* and checks its type:
if (PyString_Check(obj)) ...
if (PySequence_Check(obj))
Before doing the check, I print the passed object with PyObject_Str() and
get:
passed object: __main__.__object object at 0x040E4050
However, the C code returns true on the:
if (PySequence_Check(obj))
Why? That is not a sequence?
--
http://mail.python.org/mailman/listinfo/python-list
Re: Python Go
On 16 Nov, 10:06, Terry Reedy tjre...@udel.edu wrote: Python run well on multiple cores, you just have to use processes instead of threads. But not so trivially as to add one word to an existing function. Hence by tweak, I meant, as explained in another post, to add a keyword or just a decorator that will do what the go keyword does in go. A decorator function like @go could just call os.fork and run the function in the child. We already have a between-process Queue in multiprocessing to use as channels. Or we could have a context manager that forks in __enter__ and waitpids or exits in __exit__. The body of the with-statement would then be executed in the child process, the parent would just raise an exception to skip directly to __exit__. Not rocket science as all. Yes that would give us a new isolated process, but such isolation is present in Erlang as well. (Windows is more tricky though, as there is no efficent fork.) -- http://mail.python.org/mailman/listinfo/python-list
SCGIServer and unusal termination
Hi there, I'm playing with SCGIServer (http://vmlinux.org/cgi-bin/dwww/usr/share/doc/python-scgi/guide.html), everything works just fine, but one thing bothers me. All prints after try-except block are executed twice after the Ctrl+C is pressed! test.py: #- from scgi.scgi_server import SCGIServer n = 0 print Starting server. try: SCGIServer().serve() except (KeyboardInterrupt, SystemExit): print Exception! # print lines are executed twice (?!) n += 1 print Terminating server, attempt %d. % n n += 1 print Check n: %d. % n #- This is the output: e...@sunce:~/data/project/ScgiServer/src python test.py Starting server. ^CException! Exception! Terminating server, attempt 1. Check n: 2. Terminating server, attempt 1. Check n: 2. e...@sunce:~/data/project/ScgiServer/src If I put something else in try-except block, code after is executed normally: try: while 1: pass except (KeyboardInterrupt, SystemExit): print Exception! e...@sunce:~/data/project/ScgiServer/src python test.py Starting server. ^CException! Terminating server, attempt 1. Check n: 2. e...@sunce:~/data/project/ScgiServer/src Environment is 64bit Ubuntu with Python v2.6.4. Is there some reasonable explanation for this behaviour? Thanks in advance. -- www.vikendi.net -/- www.supergrupa.com -- http://mail.python.org/mailman/listinfo/python-list
import subprocess in python
I am a Linux user beginning to learn Python now. Below is the first Python script that I copied from the text book. It works, so it confirmed that there is python installed in my system: #!/usr/bin/env python for a in [1, 2]: for b in ['a', 'b']: print a, b But when I continue to learn Python, I come across with issue. The text book instructed me to use ipython, but ipython command is not found in my system, so I have to use python instead. However, import subprocess still failed, see below. # which python /usr/bin/python # which ipython ipython: Command not found. # python Python 2.2.3 (#1, Feb 2 2005, 12:22:48) [GCC 3.2.3 20030502 (Red Hat Linux 3.2.3-49)] on linux2 Type help, copyright, credits or license for more information. import subprocess Traceback (most recent call last): File stdin, line 1, in ? ImportError: No module named subprocess So I guess that there should be a file named subprocess.py somewhere. But there are too many files on the huge disk, I don't know where I should start to search for it. Then I tried to key in a function file python_func_00.py by myself. def pyfunc(): print Hello function # python Python 2.2.3 (#1, Feb 2 2005, 12:22:48) [GCC 3.2.3 20030502 (Red Hat Linux 3.2.3-49)] on linux2 Type help, copyright, credits or license for more information. import python_func_00 pyfunc() Traceback (most recent call last): File stdin, line 1, in ? NameError: name 'pyfunc' is not defined There's a binary file of 240 bytes created:python_func_00.pyc But as we can see above, the function pyfunc() does not work. I guess that I should add the following statement at first line of python_func_00.py, then redo the import: #!/usr/bin/env python But after adding this line and redoing the import, pyfunc() still failed like above. What's the mistake that I am making? How to solve it? Thanks. -- http://mail.python.org/mailman/listinfo/python-list
Re: import subprocess in python
On 16 Nov, 13:50, Kuhl chen_zhi...@yahoo.com wrote: Python 2.2.3 (#1, Feb 2 2005, 12:22:48) What's the mistake that I am making? How to solve it? Your Python version is too old. -- http://mail.python.org/mailman/listinfo/python-list
Re: import subprocess in python
On Mon, Nov 16, 2009 at 4:50 AM, Kuhl chen_zhi...@yahoo.com wrote: snip found in my system, so I have to use python instead. However, import subprocess still failed, see below. # which python /usr/bin/python # which ipython ipython: Command not found. # python Python 2.2.3 (#1, Feb 2 2005, 12:22:48) [GCC 3.2.3 20030502 (Red Hat Linux 3.2.3-49)] on linux2 Type help, copyright, credits or license for more information. import subprocess Traceback (most recent call last): File stdin, line 1, in ? ImportError: No module named subprocess The `subprocess` modules was added in Python 2.4. You're using Python 2.2.3; you need to update. should start to search for it. Then I tried to key in a function file python_func_00.py by myself. def pyfunc(): print Hello function # python Python 2.2.3 (#1, Feb 2 2005, 12:22:48) [GCC 3.2.3 20030502 (Red Hat Linux 3.2.3-49)] on linux2 Type help, copyright, credits or license for more information. import python_func_00 pyfunc() Traceback (most recent call last): File stdin, line 1, in ? NameError: name 'pyfunc' is not defined snip What's the mistake that I am making? How to solve it? The `import foo` statement only adds the name of the module itself to your namespace, so you need to refer to pyfunc by way of the module name. To wit: import python_func_00 python_func_00.pyfunc() Alternatively, you can specify a set of names to import from the module namespace into your own using the `from foo import bar` syntax: from python_func_00 import pyfunc pyfunc() Regarding ipython, it's a third-party package that is not part of Python itself and must be installed separately. Exactly how you do so will obviously depend on which distro you're using. Cheers, Chris -- http://blog.rebertia.com -- http://mail.python.org/mailman/listinfo/python-list
Let python call a C function pointer passed from the C Python API
I have C++ a void function pointer stored in a variable call. The pointed function takes an int and a char* as arguments. I have a python module containing this function: def yeah(x): x(int(0),text argument) return pointer called As you can see I'm trying to use the argument x of the function like a method object. In the C++ side I'm doing following (note that I only paste relevant parts of code because this system is working fine, C++ is able to call function yeah and get its return value, but only with a string- oriented test): ... PyObject *pValue; // the argument for python pValue = PyCObject_FromVoidPtr(call,destr); // destr is a void fctn ptr, required from the api. PyObject *pFunc = PyObject_GetAttrString(pModule, yeah); ... PyTuple_SetItem(pArgs, 0, pValue); // pArgs is a pyobject, the arguments, I insert pValue in it. pValue = PyObject_CallObject(pFunc, pArgs); ... It does not work. can anyone help me please? I just want python to call this function pointer. Thank you -- http://mail.python.org/mailman/listinfo/python-list
Re: Psyco on 64-bit machines
Russ P. wrote: I just stumbled across unladen swallow, a faster implementation of Python. Is it ready for operational usage? How does it compare to Psyco? I poked around their website a bit, but I don't see answers to those questions. Thanks. I've tried a few things with it. It mostly works, but it isn't actually faster at normal programs. I've been told their target is for long running processes where JIT and similar can speed up the inner loops etc etc. Certainly makes sense for google apps in python so perhaps that's the intended end use. -- Robin Becker -- http://mail.python.org/mailman/listinfo/python-list
Re: Let python call a C function pointer passed from the C Python API
On Nov 16, 5:04 am, hvictor hvic...@bluewin.ch wrote:
I have C++ a void function pointer stored in a variable call. The
pointed function takes an int and a char* as arguments.
I have a python module containing this function:
def yeah(x):
x(int(0),text argument)
return pointer called
As you can see I'm trying to use the argument x of the function like a
method object.
In the C++ side I'm doing following (note that I only paste relevant
parts of code because this system is working fine, C++ is able to call
function yeah and get its return value, but only with a string-
oriented test):
...
PyObject *pValue; // the argument for python
pValue = PyCObject_FromVoidPtr(call,destr); // destr is a void fctn
ptr, required from the api.
PyObject *pFunc = PyObject_GetAttrString(pModule, yeah);
...
PyTuple_SetItem(pArgs, 0, pValue); // pArgs is a pyobject, the
arguments, I insert pValue in it.
pValue = PyObject_CallObject(pFunc, pArgs);
...
It does not work. can anyone help me please? I just want python to
call this function pointer.
Python can't call C function pointers. You have to write a function
in C that accepts a CObject and some arguments, unpacks the arguments,
retrieves the function pointer from the CObject, and calls it. Quick
and dirty function that might do that (untested, not robust).
static PyObject* call_user_void_ptr(PyObject* self, PyObject* args) {
PyObject* cobj;
int ival;
char* sval;
void (*func)(int,char*);
if (!PyArg_ParseTuple(O!is,PyCObject_Type,cobj,ival,sval))
return 0;
func = PyCObject_AsVoidPtr(cobj);
func(ival,sval);
Py_RETURN_NONE;
}
def yeah(x):
call_user_void_ptr(x,int(i),text_argument)
print pointer called
In a pinch, you could call the function pointer from ctypes. Since
you're already writing a C extension I wouldn't recommend it as a
final solution, though.
Carl Banks
--
http://mail.python.org/mailman/listinfo/python-list
Re: Let python call a C function pointer passed from the C Python API
On 16 Nov, 14:25, Carl Banks pavlovevide...@gmail.com wrote: Python can't call C function pointers. Yes it can, use ctypes... -- http://mail.python.org/mailman/listinfo/python-list
Re: object serialization as python scripts
King animator...@gmail.com writes: Why is it easier than the above mentioned - they are *there* (except the custom xml), and just can be used. What don't they do you want to do? Other than that, and even security issues put aside, I don't see much difference between pickle and python code, except the latter being more verbose. Which suits humans, but other than that has no advantage. Diez My application is PyQt based and objects that I am trying to save are couple of QGraphicsItem instances. You can't save instances of QGraphicsItem using pickle or shelve. Custom xml format would be a real pain as you have to write code for writing/reading both. I am aware of security issue but over all there are only 5 statements I have to use to get the entire information back. I can do syntax checking and other stuff before I should execute the script. Another reason is that data should be in human readable form. Prashant Python 2.6.2 Win XP 32 Pickling should work just fine. If you cannot pickle the class with the default pickler, you can hook into the pickler protocol to tell pickle how to pickle instances of the class. Failing that you can write your own pickler class for handling the special case. Python scripts aren't really a good data format. They're not structured in a way that would be easy to parse and extract information from in a non-python context without a lot of work. -- http://mail.python.org/mailman/listinfo/python-list
Re: Calling Python functions from Excel
On Nov 15, 2:20 am, Cannonbiker lusve...@gmail.com wrote: Please I need Calling Python functions from Excel and receive result back in Excel. Can me somebody advise simplest solution please? I am more VBA programmer than Python. A couple of years ago I used MSScriptControl for this. Couldn't find a great reference just now, but here is a discussion which should give enough information: http://www.velocityreviews.com/forums/t319222-re-python-in-excel.html Check from around message 3 on. -- http://mail.python.org/mailman/listinfo/python-list
Logic operators with in statement
Hi,
I'm trying to use logical operators (or, and) with the in statement,
but I'm having some problems to understand their behavior.
In [1]: l = ['3', 'no3', 'b3']
In [2]: '3' in l
Out[2]: True
In [3]: '3' and '4' in l
Out[3]: False
In [4]: '3' and 'no3' in l
Out[4]: True
This seems to work as I expected.
In [5]: '3' and 'no3' or '3' and '4' in l
Out[5]: 'no3'
In [6]: ('3' and 'no3') or ('3' and '4') in l
Out[6]: 'no3'
I don't understand these outputs.
---
In [7]: (('3' and 'no3') or ('3' and '4')) in l
Out[7]: True
In [10]: (('b3' and '4') or ('3' and 'no3')) in l
Out[10]: False
Here I expected to get True in the second case too, so clearly I don't
really get how they work.
Can you help me?
What I really need is to create a sequence of if statements to check
the presence of elements in a list, because some of them are mutually
exclusive, so if for example there are both 3 and no3 it should
return an error.
Thanks,
Carlo
--
http://mail.python.org/mailman/listinfo/python-list
Re: Code for finding the 1000th prime
On Nov 15, 10:02 am, Diez B. Roggisch de...@nospam.web.de wrote: mrholtsr schrieb: I am absolutely new to python and barely past beginner in programming. Also I am not a mathematician. Can some one give me pointers for finding the 1000th. prime for a course I am taking over the internet on Introduction to Computer Science and Programming. Thanks, Ray Do you really think we are so retarded that we don't remember you posted the same question a week ago? Diez Mea Culpa. I didn't realize at the time that this group was the same as the newsletter. Won't do it again. -- http://mail.python.org/mailman/listinfo/python-list
Re: Psyco on 64-bit machines
Russ P. wrote: Would it make sense to compile Python in the 32-bit compatibility mode so I can use Psyco? What would I lose in that mode, if anything? Thanks. You won't be able to access large amounts of memory in 32 bit mode. Also, the x86-64 mode has more CPU registers than x86 mode, so Python will typically run faster in 64 bit mode (this is more pronounced in AMD processors, in my experience). It will depend on your application whether 32 bit mode plus Psyco is faster than 64 bit mode. Jeremy -- Jeremy Sanders http://www.jeremysanders.net/ -- http://mail.python.org/mailman/listinfo/python-list
Newsgroup for beginners
Is there a Python newsgroup for those who are strictly beginners at programming and python? -- http://mail.python.org/mailman/listinfo/python-list
Re: Logic operators with in statement
Sorry for replying to myself, but I think I understood why I was wrong.
The correct statement should be something like this:
In [13]: ('b3' and '5') in l or ('3' and 'b3') in l
Out[13]: True
--
http://mail.python.org/mailman/listinfo/python-list
Re: Code for finding the 1000th prime
On 15 Nov, 15:30, mrholtsr mrhol...@gmail.com wrote: I am absolutely new to python and barely past beginner in programming. Also I am not a mathematician. Can some one give me pointers for finding the 1000th. prime for a course I am taking over the internet on Introduction to Computer Science and Programming. Thanks, Ray print 7919 -- http://mail.python.org/mailman/listinfo/python-list
Re: Newsgroup for beginners
mrholtsr wrote: Is there a Python newsgroup for those who are strictly beginners at programming and python? Yes, the tutor-list. http://mail.python.org/mailman/listinfo/tutor Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: Logic operators with in statement
On 02:02 pm, mr.spoo...@gmail.com wrote:
Hi,
I'm trying to use logical operators (or, and) with the in statement,
but I'm having some problems to understand their behavior.
and and or have no particular interaction with in.
In [1]: l = ['3', 'no3', 'b3']
In [2]: '3' in l
Out[2]: True
In [3]: '3' and '4' in l
Out[3]: False
In [4]: '3' and 'no3' in l
Out[4]: True
This seems to work as I expected.
What this actually does is '3' and ('no3' in l). So it might have
produced the result you expected, but it didn't work how you expected.
:)
Jean-Paul
--
http://mail.python.org/mailman/listinfo/python-list
Re: Newsgroup for beginners
On Mon, Nov 16, 2009 at 6:01 AM, mrholtsr mrhol...@gmail.com wrote: Is there a Python newsgroup for those who are strictly beginners at programming and python? python-tutor: http://mail.python.org/mailman/listinfo/tutor Cheers, Chris -- http://blog.rebertia.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Logic operators with in statement
On Mon, Nov 16, 2009 at 6:02 AM, Mr.SpOOn mr.spoo...@gmail.com wrote:
Hi,
I'm trying to use logical operators (or, and) with the in statement,
but I'm having some problems to understand their behavior.
In [1]: l = ['3', 'no3', 'b3']
In [2]: '3' in l
Out[2]: True
In [3]: '3' and '4' in l
Out[3]: False
In [4]: '3' and 'no3' in l
Out[4]: True
This seems to work as I expected.
No, it doesn't. You are misinterpreting. Membership tests via `in` do
NOT distribute over `and` and `or`.
'3' and '4' in l
is equivalent to:
('3') and ('4' in l)
Recall that non-empty sequences and containers are conventionally True
in Python, so your expression is logically equivalent to:
'4' in l
With '3' not being checked for membership at all.
To check multiple items for membership in a contains, you must write
each `in` test separately and then conjoin then by the appropriate
boolean operator:
'3' in l and '4' in l
Cheers,
Chris
--
http://blog.rebertia.com
--
http://mail.python.org/mailman/listinfo/python-list
Re: Logic operators with in statement
On Tue, Nov 17, 2009 at 12:02 AM, Mr.SpOOn mr.spoo...@gmail.com wrote: Hi, I'm trying to use logical operators (or, and) with the in statement, but I'm having some problems to understand their behavior. Hey Carlo, I think your issue here is mistaking 'in' as a statement. It's just another logic operator, much like 'and' and 'or'... it's not a statement in itself. At least, I don't think that's how you'd call 'in'. You have to remember that Python's logical operators (and, or) works slightly different than most languages. It doesn't return True or False, if the things compared aren't boolean values. Instead, it returns the first thing that makes the decision. For example a statement such as '3' and '4' '4' returns the string literal 4. 1. Python's AND operator returns the first element if the first one is False; else, it returns the second element. That's all it does. Python's OR operator returns the first element if the first one is True; else, it returns the second element. Think about it. It's a little strange, but they don't return a pure Boolean value. 2. Only the empty string is considered False. Any non-empty strings have True values. 3. The proper way of using the in operator is probably such: (There may be a better way I'm not aware of.) '3' in l and '4' in l False '3' in l and 'no3' in l True AND operator has a higher precedence, so you don't need any brackets here, I think. But anyway, you have to use it like that. So that's something you'll have to fix first. What I really need is to create a sequence of if statements to check the presence of elements in a list, because some of them are mutually exclusive, so if for example there are both 3 and no3 it should return an error One idea I can think of is to have a presence count; assuming the input is non-repeating, you increase this count by 1, starting at 0. If you get anything above one, return this error you speak of, and that might be a good start. Good luck, Xav -- http://mail.python.org/mailman/listinfo/python-list
Re: Logic operators with in statement
On Mon, Nov 16, 2009 at 6:08 AM, Mr.SpOOn mr.spoo...@gmail.com wrote:
Sorry for replying to myself, but I think I understood why I was wrong.
The correct statement should be something like this:
In [13]: ('b3' and '5') in l or ('3' and 'b3') in l
Out[13]: True
No, you've just run into another misunderstanding.
Given the expression `X and Y`:
If bool(X) is False, it evaluates to X.
Otherwise, it evaluates to Y.
In other words, the subexpression which ends up determining the truth
of the conjunction is what the conjunction evaluates to. `or` works
similarly.
This allows for tricky tricks like:
foo = possiblyFalse or default # use default if given value is false
Thus, due to the parentheses, your expression is equivalent to:
'5' in l or 'b3' in l
Which I trust is not what you intended.
Again, you need to write separate `in`s for each item you need to
check the membership of:
('b3' in l and '5' in l) or ('3' in l and 'b3' in l)
Cheers,
Chris
--
Python language lawyer at your service
http://blog.rebertia.com
--
http://mail.python.org/mailman/listinfo/python-list
Re: Logic operators with in statement
On Tue, Nov 17, 2009 at 12:08 AM, Mr.SpOOn mr.spoo...@gmail.com wrote:
Sorry for replying to myself, but I think I understood why I was wrong.
The correct statement should be something like this:
In [13]: ('b3' and '5') in l or ('3' and 'b3') in l
Out[13]: True
Carlo, I'm not sure what that achieves. Care to enlighten me?
Cheers,
Xav
--
http://mail.python.org/mailman/listinfo/python-list
Re: Logic operators with in statement
Here I expected to get True in the second case too, so clearly I don't
really get how they work.
You're seeing short-circuit evaluation:
3 or 4 # true
'3'
'4' or '3' # true
'4'
'4' in l# false
False
'3' or False # true
'3'
'4' or '42' in l # true: same as '4' or ('42' in l)
'4'
'4' or '42'
'4'
('4' or '42') in l # true: same as '4' in l
'4'
It just happens that sometimes you get unexpected results that
happen to be right because of how Python handles strings/numbers
as booleans and order-of-operations.
What I really need is to create a sequence of if statements to check
the presence of elements in a list, because some of them are mutually
exclusive, so if for example there are both 3 and no3 it should
return an error.
The in operator only checks containment of one item, not
multiples, so you have to manage the checking yourself. This is
fairly easy with the any()/all() functions added in 2.5:
any(i in l for i in (3, 4))
all(i in l for i in (3, 4))
For more complex containment testing, using sets will be more
efficient and offers a richer family of batch operators
(contains, intersection, union, difference, issubset, issuperset)
-tkc
--
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Re: Newsgroup for beginners
mrholtsr wrote: Is there a Python newsgroup for those who are strictly beginners at programming and python? http://mail.python.org/mailman/listinfo/tutor -tkc -- http://mail.python.org/mailman/listinfo/python-list
Re: Logic operators with in statement
On Mon, Nov 16, 2009 at 6:23 AM, Xavier Ho cont...@xavierho.com wrote: snip '3' in l and 'no3' in l True AND operator has a higher precedence, so you don't need any brackets here, I think. But anyway, you have to use it like that. So that's something you'll have to fix first. Er, you mean lower precedence. Higher precedence means it would bind tighter, thus the expression would mean: '3' in (l and 'no3') in l which is certainly incorrect. Cheers, Chris -- http://blog.rebertia.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Go
Terry Reedy wrote: It seems to me that generators are already 'channels' that connect the calling code to the __next__ method, a semi-coroutine based on the body of the generator function. At present, the next method waits until an object is requested. Then it goes into action, yields an object, and rests again. For parallel operations, we need eager, anticipatory evaluation that produces things that *will* be needed rather than lazy evaluation of things that *are* needed and whose absence is holding up everything else. Yes, generators look very much like channels. The obvious thing, from where I'm sitting, is to have a function called channel that takes an iterator, runs it in a different thread/process/goroutine, and returns an iterator that reads from the channel. A single threaded version would look very much like iter so let's use iter to get a working example: #!/usr/bin/python2 -u channel = iter # placeholder for missing feature def generate(): i = 2 while True: yield i i += 1 def filter(input, prime): for i in input: if i%prime != 0: yield i ch = channel(generate()) try: while True: prime = ch.next() print prime ch = channel(filter(ch, prime)) except IOError: pass That works fine in a single thread. It's close to the original go example, hence the evil shadowing of a builtin. I don't think the channel function would present any problems given an appropriate library to wrap. I got something like this working with Jython and the E language but, as I recall, had an accident and lost the code. If somebody wants to implement it using multiprocessing, go to it! Graham -- http://mail.python.org/mailman/listinfo/python-list
Re: python simply not scaleable enough for google?
On 16 Nov, 05:51, sturlamolden sturlamol...@yahoo.no wrote: NASA can find money to build a space telescope and put it in orbit. They don't find money to create a faster Python, which they use for analyzing the data. Is the analysis in Python really what slows it all down? Google is a multi-billion dollar business. They are using Python extensively. Yes I know about Unladen Swallow, but why can't they put 1 mill dollar into making a fast Python? Isn't this where we need those Ohloh figures on how much Unladen Swallow is worth? ;-) I think Google is one of those organisations where that Steve Jobs mentality of shaving time off a once-per-day activity actually pays off. A few more cycles here and there is arguably nothing to us, but it's a few kW when running on thousands of Google nodes. And then there is IBM and Cern's Blue Brain project. They can set up the fastest supercomputer known to man, but finance a faster Python? No... Businesses and organisations generally don't spend any more money than they need to. And if choosing another technology is cheaper for future work then they'll just do that instead. In a sense, Python's extensibility using C, C++ and Fortran have helped adoption of the language considerably, but it hasn't necessarily encouraged a focus on performance. Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: (unknown)
On Nov 15, 2009, at 11:08 AM, Gabriel Genellina wrote: En Fri, 13 Nov 2009 16:05:26 -0300, Ronn Ross ronn.r...@gmail.com escribió: I'm attempting to convert latitude and longitude coordinates from degrees minutes and second to decimal form. I would like to go from: N39 42 36.3 W77 42 51.5 to: -77.739855,39.70 Does anyone know of a library or some existing out their to help with this conversion? Should be: decimal = degrees + minutes/60.0 + seconds/3600.0 N,E are positive; S,W are negative. But the above numbers don't match. It is more complicated than that. For negative numbers the value is degrees -minutes/60. - seconds/3600. And people always trip up on numbers that start with -00 :) Cheers Tommy -- http://mail.python.org/mailman/listinfo/python-list
Image to SVG conversion with Python
I need to convert JPEG and PNG files to SVG. I'm currently using PIL to generate the JPEG/PNG files to begin with. However, I need to be able to scale the generated images up in size without a loss of image quality. Using SVG seems to be the best way to do this, other than generating the images in the maximum size/resolution in the first place, which would be too resource intensive. I've looked around online and have found some tools for creating SVGs but none for converting an image into SVG. Does anyone have any experience doing this? What would be the best way to go about this? Thanks, Carlo -- http://mail.python.org/mailman/listinfo/python-list
Re: C api question and determining PyObject type
En Mon, 16 Nov 2009 07:44:34 -0300, lallous lall...@lgwm.org escribió:
Actually, the object class is defined as:
class __object(object):
def __getitem__(self, idx):
return getattr(self, idx)
Anyway, now I check like this:
bool PyIsSequenceType(PyObject *obj)
{
if (!PySequence_Check(obj))
return false;
Py_ssize_t sz = PySequence_Size(obj);
if (sz == -1 || PyErr_Occurred() != NULL)
{
PyErr_Clear();
return false;
}
return true;
}
I don't like it, any other suggestions?
Yes: find another name for the thing you're checking for. It's not the
same as a sequence in the Python sense.
Perhaps you want to consider your type a mapping? Sequences and mappings
have a lot in common (mappings have length too.) In C you have separate
slots tp_as_sequence, tp_as_mapping; but in Python code, __getitem__ is
used for both meanings (and goes into both set of pointers.) tp_as_mapping
takes precedence over tp_as_sequence.
--
Gabriel Genellina
--
http://mail.python.org/mailman/listinfo/python-list
Re: C api question and determining PyObject type
En Mon, 16 Nov 2009 07:44:34 -0300, lallous lall...@lgwm.org escribió:
Actually, the object class is defined as:
class __object(object):
def __getitem__(self, idx):
return getattr(self, idx)
Anyway, now I check like this:
bool PyIsSequenceType(PyObject *obj)
{
if (!PySequence_Check(obj))
return false;
Py_ssize_t sz = PySequence_Size(obj);
if (sz == -1 || PyErr_Occurred() != NULL)
{
PyErr_Clear();
return false;
}
return true;
}
I don't like it, any other suggestions?
Yes: find another name for the thing you're checking for. It's not the
same as a sequence in the Python sense.
Perhaps you want to consider your type a mapping? Sequences and mappings
have a lot in common (mappings have length too.) In C you have separate
slots tp_as_sequence, tp_as_mapping; but in Python code, __getitem__ is
used for both meanings (and goes into both set of pointers.) tp_as_mapping
takes precedence over tp_as_sequence.
--
Gabriel Genellina
--
http://mail.python.org/mailman/listinfo/python-list
Python-URL! - weekly Python news and links (Nov 16)
QOTW: The promise is 'batteries included.' Nobody promised you a nickel metal hydride battery that you can use as a replacement in your Prius. - Stephen J. Turnbull http://mail.python.org/pipermail/python-dev/2009-November/094014.html Google's new language, Go, has similarities to Python: http://groups.google.com/group/comp.lang.python/t/c1c4a8fe741c689a/ Is Python scalable enough for Google (or any other huge application)? http://groups.google.com/group/comp.lang.python/t/ceef2ae6b4472b61/ Is it possible to get the physical memory address of a variable in python? http://groups.google.com/group/comp.lang.python/t/969462b9a3b452/ Serialize objects as Python code: http://groups.google.com/group/comp.lang.python/t/98536e7910e65256/ Overriding __getitem__ for a subclass of dict: http://groups.google.com/group/comp.lang.python/t/d9b822119fc0917c/ Ensure a script is run with a certain range of Python versions: http://groups.google.com/group/comp.lang.python/t/d21a492be99c90e8/ How to install applications when Python is not already present: http://groups.google.com/group/comp.lang.python/t/495794a40d18fbc/ Turtle graphics are just for kids - or not? Its advantages when teaching Python programming: http://groups.google.com/group/comp.lang.python/t/d55388b0fdd9ed2f/ Using dynamic property names: http://groups.google.com/group/comp.lang.python/t/f7b8829c97dcc3f9/ How can a module react differently when imported from one place or another? http://groups.google.com/group/comp.lang.python/t/da162dc08f1c3550/ Sharing distributed objects between Python and C++: http://groups.google.com/group/comp.lang.python/t/5a567a1a180511eb/ Beware: threads + import don't mix well! http://groups.google.com/group/comp.lang.python/t/a60c83590a016528/ locals() and frame.f_locals return old data: http://groups.google.com/group/comp.lang.python/t/fa17941218c6e89e/ Instantiate classes using names from the command line: http://groups.google.com/group/comp.lang.python/t/d597a1a42b88c0d1/ New syntax proposal: if some_expression as x: do_something_with(x) http://groups.google.com/group/comp.lang.python/t/55e7578903747dc4/ Everything Python-related you want is probably one or two clicks away in these pages: Python.org's Python Language Website is the traditional center of Pythonia http://www.python.org Notice especially the master FAQ http://www.python.org/doc/FAQ.html PythonWare complements the digest you're reading with the marvelous daily python url http://www.pythonware.com/daily Just beginning with Python? This page is a great place to start: http://wiki.python.org/moin/BeginnersGuide/Programmers The Python Papers aims to publish the efforts of Python enthusiasts: http://pythonpapers.org/ The Python Magazine is a technical monthly devoted to Python: http://pythonmagazine.com Readers have recommended the Planet site: http://planet.python.org comp.lang.python.announce announces new Python software. Be sure to scan this newsgroup weekly. http://groups.google.com/group/comp.lang.python.announce/topics Python411 indexes podcasts ... to help people learn Python ... Updates appear more-than-weekly: http://www.awaretek.com/python/index.html The Python Package Index catalogues packages. http://www.python.org/pypi/ Much of Python's real work takes place on Special-Interest Group mailing lists http://www.python.org/sigs/ Python Success Stories--from air-traffic control to on-line match-making--can inspire you or decision-makers to whom you're subject with a vision of what the language makes practical. http://www.pythonology.com/success The Python Software Foundation (PSF) has replaced the Python Consortium as an independent nexus of activity. It has official responsibility for Python's development and maintenance. http://www.python.org/psf/ Among the ways you can support PSF is with a donation. http://www.python.org/psf/donations/ The Summary of Python Tracker Issues is an automatically generated report summarizing new bugs, closed ones, and patch submissions. http://search.gmane.org/?author=status%40bugs.python.orggroup=gmane.comp.python.develsort=date Although unmaintained since 2002, the Cetus collection of Python hyperlinks retains a few gems. http://www.cetus-links.org/oo_python.html Python FAQTS http://python.faqts.com/ The Cookbook is a collaborative effort to capture useful and interesting recipes.
Re: (unknown)
En Mon, 16 Nov 2009 11:11:20 -0300, Tommy Grav tg...@me.com escribió: On Nov 15, 2009, at 11:08 AM, Gabriel Genellina wrote: En Fri, 13 Nov 2009 16:05:26 -0300, Ronn Ross ronn.r...@gmail.com escribió: I'm attempting to convert latitude and longitude coordinates from degrees minutes and second to decimal form. I would like to go from: N39 42 36.3 W77 42 51.5 to: -77.739855,39.70 decimal = degrees + minutes/60.0 + seconds/3600.0 N,E are positive; S,W are negative. But the above numbers don't match. It is more complicated than that. For negative numbers the value is degrees -minutes/60. - seconds/3600. And people always trip up on numbers that start with -00 :) I set the sign of the result *after* computing it, so it doesn't matter. py 39 + 42/60.0 + 36.3/3600 39.7100837 py 77 + 42/60.0 + 51.5/3600 77.7143055 Either the example above is incorrect, or there is another thing involved. -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
Re: A terminators' club for clp
kj wrote: In 7x3a4i56u7@ruckus.brouhaha.com Paul Rubin http://phr...@nospam.invalid writes: kj no.em...@please.post writes: frequent* clp posters the ability to *easily* delete spam from the comp.lang.python server? Um, this is usenet; there is no comp.lang.python server. Are you saying you want a moderated newsgroup? Hmm, maybe this group is busy enough that there is some merit to that idea. Sorry, I had a mistaken view of how usenet was implemented. But yeah, I guess I'm thinking of a moderated newsgroup, but with a large number of moderators working in parallel, and a very lax acceptance policy. The goal is to filter out only the obvious spam, and let through all the other non-spam traffic as quickly as possible... What do I mean by obvious spam? Well, among the most recent messages (that have survived my killfile policies) I see the following subject lines: * Top 10 US mp3 songs.Cheers * www.find68.com cheaper nike shoes g-satr kidrobot hoodies ed hardy star red monkey gino green global true religion ed-hardy kidrobot jeans hoodies china supplier wholesaler exporters,manufacture * jobs in france jobs in france for english people jobs in france for foreigners jobs in france for australians jobs in france for foreigners jobs in france for new zealanders jobs paris jobs http://jobs-in-fr ance.blogspot.com/ * germany jobs germany job sites germany job search jobs in germany german jobs germany jobs it germany jobs for foreigners germany jobsite germany jobs in english on http://jobs-germany.blogspot.com/ Those look pretty obvious to me. But, as I already showed, I'm out of my depth here, so I'd better shut up. Some usenet newsgroups were/are moderated either by a robot, a person, or a team (as you suggested). But a particular newsgroup has to be set up that way from the beginning. Last I knew, it wan/is? difficult to convert an unmoderated group to moderation. Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: Newsgroup for beginners
mrholtsr wrote: Is there a Python newsgroup for those who are strictly beginners at programming and python? gmane.comp.python.tutor, which I believe mirrors the tutor-list -- http://mail.python.org/mailman/listinfo/python-list
Re: Image to SVG conversion with Python
Carlo DiCelico wrote: I need to convert JPEG and PNG files to SVG. I'm currently using PIL to generate the JPEG/PNG files to begin with. However, I need to be able to scale the generated images up in size without a loss of image quality. Using SVG seems to be the best way to do this, other than generating the images in the maximum size/resolution in the first place, which would be too resource intensive. I've looked around online and have found some tools for creating SVGs but none for converting an image into SVG. Does anyone have any experience doing this? What would be the best way to go about this? Thanks, Carlo I have no direct experience with SVG, but have used and analyzed other formats. I expect it's unreasonable to convert jpg or png files to SVG. The latter is a vector format, and can't efficiently represent pixels, which is all you have in the jpg files. And even if you did it brute force, it still wouldn't scale any better than the original jpg. If the jpg file was generated from lines, and wasn't too crowded, it *might* be possible to analyze it to reconstruct the vectors, but it would be both very slow, and inaccurate. In Photoshop PSD files, you can have vector layers and RGB layers (plus other kinds). You convert a vector layer (such as text) to bits by rasterizing (or flattening). And once you do, it no longer scales cleanly. For instance, when I'm sending composite images to a printer, I get much better quality sending the raster portion separate from the text, either as layers in a PSD file, or in a PDF file, or even as two separate files that they will merge later. (In that case, I usually send a low-res flattened file, so they can see how it's supposed to look) I'd say you should change your python code to generate the svg files first (perhaps using http://code.activestate.com/recipes/325823/ ) Then you might want to use ( http://www.imagemagick.org/script/index.php ) to convert it to jpg or other format. DaveA -- http://mail.python.org/mailman/listinfo/python-list
Language mavens: Is there a programming with if then else ENDIF syntax?
This is a question for the language mavens that I know hang out here.
It is not Python related, except that recent comparisons of Python to
Google's new Go language brought it to mind.
NOTE that this is *not* a suggestion to change Python. I like Python
just the way it is. I'm just curious about language design.
For a long time I've wondered why languages still use blocks
(delimited by do/end, begin/end, { } , etc.) in ifThenElse statements.
I've often thought that a language with this kind of block-free syntax
would be nice and intuitive:
if condition then
do stuff
elif condition then
do stuff
else
do stuff
endif
Note that you do not need block delimiters.
Obviously, you could make a more Pythonesque syntax by using a colon
rather then then for the condition terminator. You could make it
more PL/I-like by using do, etc.
You can write shell scripts using if ... fi, but other than that I
don't recall a language with this kind of syntax.
Does anybody know a language with this kind of syntax for
ifThenElseEndif?
Is there any particular reason why this might be a *bad* language-
design idea?
--
http://mail.python.org/mailman/listinfo/python-list
Re: Language mavens: Is there a programming with if then else ENDIF syntax?
Steve Ferg wrote: . if condition then do stuff elif condition then do stuff else do stuff endif Note that you do not need block delimiters. Obviously, you could make a more Pythonesque syntax by using a colon rather then then for the condition terminator. You could make it more PL/I-like by using do, etc. You can write shell scripts using if ... fi, but other than that I don't recall a language with this kind of syntax. Does anybody know a language with this kind of syntax for ifThenElseEndif? ... modern sh seems to use this with fi as endif eg ~: $ if true; then echo true elif false; then echo false else echo hostile logic fi true ~: $ -- Robin Becker -- http://mail.python.org/mailman/listinfo/python-list
Re: Image to SVG conversion with Python
On Nov 16, 11:48 am, Dave Angel da...@ieee.org wrote: Carlo DiCelico wrote: I need to convert JPEG and PNG files to SVG. I'm currently using PIL to generate the JPEG/PNG files to begin with. However, I need to be able to scale the generated images up in size without a loss of image quality. Using SVG seems to be the best way to do this, other than generating the images in the maximum size/resolution in the first place, which would be too resource intensive. I've looked around online and have found some tools for creating SVGs but none for converting an image into SVG. Does anyone have any experience doing this? What would be the best way to go about this? Thanks, Carlo I have no direct experience with SVG, but have used and analyzed other formats. I expect it's unreasonable to convert jpg or png files to SVG. The latter is a vector format, and can't efficiently represent pixels, which is all you have in the jpg files. And even if you did it brute force, it still wouldn't scale any better than the original jpg. If the jpg file was generated from lines, and wasn't too crowded, it *might* be possible to analyze it to reconstruct the vectors, but it would be both very slow, and inaccurate. In Photoshop PSD files, you can have vector layers and RGB layers (plus other kinds). You convert a vector layer (such as text) to bits by rasterizing (or flattening). And once you do, it no longer scales cleanly. For instance, when I'm sending composite images to a printer, I get much better quality sending the raster portion separate from the text, either as layers in a PSD file, or in a PDF file, or even as two separate files that they will merge later. (In that case, I usually send a low-res flattened file, so they can see how it's supposed to look) I'd say you should change your python code to generate the svg files first (perhaps usinghttp://code.activestate.com/recipes/325823/) Then you might want to use (http://www.imagemagick.org/script/index.php ) to convert it to jpg or other format. DaveA Thanks, this makes perfect sense. -- http://mail.python.org/mailman/listinfo/python-list
Re: Language mavens: Is there a programming with if then else ENDIF syntax?
On 16 Nov, 16:54, Steve Ferg steve.ferg.bitbuc...@gmail.com wrote:
This is a question for the language mavens that I know hang out here.
It is not Python related, except that recent comparisons of Python to
Google's new Go language brought it to mind.
NOTE that this is *not* a suggestion to change Python. I like Python
just the way it is. I'm just curious about language design.
For a long time I've wondered why languages still use blocks
(delimited by do/end, begin/end, { } , etc.) in ifThenElse statements.
I've often thought that a language with this kind of block-free syntax
would be nice and intuitive:
if condition then
do stuff
elif condition then
do stuff
else
do stuff
endif
Note that you do not need block delimiters.
Obviously, you could make a more Pythonesque syntax by using a colon
rather then then for the condition terminator. You could make it
more PL/I-like by using do, etc.
You can write shell scripts using if ... fi, but other than that I
don't recall a language with this kind of syntax.
Does anybody know a language with this kind of syntax for
ifThenElseEndif?
Is there any particular reason why this might be a *bad* language-
design idea?
There are some. For example, Ada uses similar. See
http://en.wikipedia.org/wiki/Ada_%28programming_language%29#Control_structures
These other newsgroups may be of interest:
comp.programming
comp.lang.misc
The latter is used by people designing programming languages where you
can find knowledgeable comments aplenty.
James
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Re: Language mavens: Is there a programming with if then else ENDIF syntax?
Steve Ferg steve.ferg.bitbuc...@gmail.com wrote in
news:ff92db5b-9cb0-4a72-b339-2c5ac02fb...@p36g2000vbn.googlegro
ups.com:
This is a question for the language mavens that I know hang
out here. It is not Python related, except that recent
comparisons of Python to Google's new Go language brought it
to mind.
NOTE that this is *not* a suggestion to change Python. I
like Python just the way it is. I'm just curious about
language design.
For a long time I've wondered why languages still use blocks
(delimited by do/end, begin/end, { } , etc.) in ifThenElse
statements.
I've often thought that a language with this kind of
block-free syntax would be nice and intuitive:
if condition then
do stuff
elif condition then
do stuff
else
do stuff
endif
Note that you do not need block delimiters.
Obviously, you could make a more Pythonesque syntax by using
a colon rather then then for the condition terminator.
You could make it more PL/I-like by using do, etc.
You can write shell scripts using if ... fi, but other than
that I don't recall a language with this kind of syntax.
Does anybody know a language with this kind of syntax for
ifThenElseEndif?
Is there any particular reason why this might be a *bad*
language- design idea?
I believe MATLAB has similar if syntax - please correct me if I'm
wrong.
From
http://www.mathworks.com/access/helpdesk/help/techdoc/ref/if.html
The if function can be used alone or with the else and elseif
functions. When using elseif and/or else within an if statement,
the general form of the statement is
if expression1
statements1
elseif expression2
statements2
else
statements3
end
Adrian
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Re: Redirect stdout to a buffer [Errno 9]
On Nov 15, 5:28 pm, Ecir Hana ecir.h...@gmail.com wrote: Hello, I'm trying to write a simple Win32 app, which may run some Python scripts. Since it is a Windows GUI app, I would like to redirect all output (Python print, C printf, fprinf stderr, ...) to a text area inside the app. In other words, I'm trying to log all the output from the app (C, Python) to a window. So far, this works for C printf(): int fds[2]; _pipe(fds, 1024, O_TEXT); _dup2(fds[1], 1); ... and then I read from pipe's read-end and append the text to the text area. But when I try to run: Py_Initialize(); PyRun_SimpleString(print 'abc'); Py_Finalize(); I get an error: IOError: [Errno 9] Bad file descriptor What am I doing wrong? How to redirect standard IO, both for C and for Python? PS: Maybe I'm doind something wrong, but SetStdHandle() does not work at all Also, maybe this matters: it's on WinXP, Python 2.6 and MinGW GCC. -- http://mail.python.org/mailman/listinfo/python-list
Re: Newsgroup for beginners
On Nov 16, 8:35 am, Terry Reedy tjre...@udel.edu wrote: mrholtsr wrote: Is there a Python newsgroup for those who are strictly beginners at programming and python? gmane.comp.python.tutor, which I believe mirrors the tutor-list There also is a beginner's forum at python-forum.org: http://www.python-forum.org/pythonforum/viewforum.php?f=3 -- http://mail.python.org/mailman/listinfo/python-list
Re: Language mavens: Is there a programming with if then else ENDIF syntax?
Steve Ferg wrote:
This is a question for the language mavens that I know hang out here.
It is not Python related, except that recent comparisons of Python to
Google's new Go language brought it to mind.
NOTE that this is *not* a suggestion to change Python. I like Python
just the way it is. I'm just curious about language design.
For a long time I've wondered why languages still use blocks
(delimited by do/end, begin/end, { } , etc.) in ifThenElse statements.
I've often thought that a language with this kind of block-free syntax
would be nice and intuitive:
if condition then
do stuff
elif condition then
do stuff
else
do stuff
endif
Note that you do not need block delimiters.
Obviously, you could make a more Pythonesque syntax by using a colon
rather then then for the condition terminator. You could make it
more PL/I-like by using do, etc.
You can write shell scripts using if ... fi, but other than that I
don't recall a language with this kind of syntax.
Does anybody know a language with this kind of syntax for
ifThenElseEndif?
Is there any particular reason why this might be a *bad* language-
design idea?
Ada and Turing have:
if condition then
do stuff
elsif condition then
do stuff
else
do stuff
end if
Comal has:
if condition then
do stuff
elif condition then
do stuff
else
do stuff
end if
Modula-2 has:
if condition then
do stuff
elsif condition then
do stuff
else
do stuff
end
--
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Re: Language mavens: Is there a programming with if then else ENDIF syntax?
Robin Becker wrote: ... modern sh seems to use this with fi as endif eg ~: $ if true; then echo true elif false; then echo false else echo hostile logic fi true ~: $ I meant to say that since sh uses this construct it cannot be too bad as a language construct since the world is built with sh and bash and similar. Of course that's a bad argument since there's more cobol than everything else put together (allegedly). -- Robin Becker -- http://mail.python.org/mailman/listinfo/python-list
Re: import subprocess in python
On Mon, 16 Nov 2009 04:58:00 -0800, sturlamolden wrote: On 16 Nov, 13:50, Kuhl chen_zhi...@yahoo.com wrote: Python 2.2.3 (#1, Feb 2 2005, 12:22:48) What's the mistake that I am making? How to solve it? Your Python version is too old. Your Python version is *way* too old. If you're lucky, people who use features of Python 2.5 or 2.6 will mention that you need Python 2.5 or 2.6, but having at least Python 2.4 is generally taken for granted. -- http://mail.python.org/mailman/listinfo/python-list
Re: Image to SVG conversion with Python
On Mon, 16 Nov 2009 07:19:49 -0800, Carlo DiCelico wrote: I need to convert JPEG and PNG files to SVG. I'm currently using PIL to generate the JPEG/PNG files to begin with. However, I need to be able to scale the generated images up in size without a loss of image quality. Using SVG seems to be the best way to do this, other than generating the images in the maximum size/resolution in the first place, which would be too resource intensive. I've looked around online and have found some tools for creating SVGs but none for converting an image into SVG. Does anyone have any experience doing this? What would be the best way to go about this? JPEG/PNG are raster formats, SVG is a vector format. To convert raster graphics to vector graphics, you need a tracing program (aka image tracing, vector tracing, vectorizing), e.g. potrace (this program is often bundled with InkScape): http://potrace.sourceforge.net/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Language mavens: Is there a programming with if then else ENDIF syntax?
On Mon, 16 Nov 2009 08:54:28 -0800, Steve Ferg wrote:
For a long time I've wondered why languages still use blocks
(delimited by do/end, begin/end, { } , etc.) in ifThenElse statements.
I've often thought that a language with this kind of block-free syntax
would be nice and intuitive:
if condition then
do stuff
elif condition then
do stuff
else
do stuff
endif
Note that you do not need block delimiters.
Does anybody know a language with this kind of syntax for
ifThenElseEndif?
BBC BASIC V had if/then/else/endif (it didn't have elif).
make has if/else/else/endif (it doesn't have a dedicated elif, but
else if ... behaves like elif rather than starting a nested if).
Is there any particular reason why this might be a *bad* language-
design idea?
Blocks can be useful for other reasons (e.g. limiting variable scope), so
if you already have them, you don't need to provide dedicated blocks
for control constructs.
--
http://mail.python.org/mailman/listinfo/python-list
Re: Redirect stdout to a buffer [Errno 9]
En Mon, 16 Nov 2009 14:17:52 -0300, Ecir Hana ecir.h...@gmail.com
escribió:
I'm trying to write a simple Win32 app, which may run some Python
scripts. Since it is a Windows GUI app, I would like to redirect all
output (Python print, C printf, fprinf stderr, ...) to a text area
inside the app. In other words, I'm trying to log all the output from
the app (C, Python) to a window. So far, this works for C printf():
[...]
PS: Maybe I'm doind something wrong, but SetStdHandle() does not work
at all
This worked for me:
#include windows.h
#include Python.h
int main()
{
HANDLE hReadPipe, hWritePipe;
DWORD nr, nw;
char buffer[100];
CreatePipe(
hReadPipe,
hWritePipe,
NULL,
1024);
SetStdHandle(STD_OUTPUT_HANDLE, hWritePipe);
Py_Initialize();
PyRun_SimpleString(print 'from Python');
Py_Finalize();
puts(from C\n);
CloseHandle(hWritePipe);
ReadFile(hReadPipe, buffer, 19, nr, NULL);
CloseHandle(hReadPipe);
WriteFile(GetStdHandle(STD_ERROR_HANDLE), buffer, nr, nw, NULL);
}
Also, maybe this matters: it's on WinXP, Python 2.6 and MinGW GCC.
I'm using Visual Studio 2008 Express Edition.
--
Gabriel Genellina
--
http://mail.python.org/mailman/listinfo/python-list
RE: tkFileDialog question
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-Original Message-
From: python-list-bounces+mmitchell=transparent@python.org
[mailto:python-list-bounces+mmitchell=transparent@python.org] On
Behalf Of r
Sent: Monday, November 16, 2009 12:16 AM
To: python-list@python.org
Subject: Re: tkFileDialog question
Matt,
There is also a nice thing you need to know about Python if you
already do not know. That is the fact that all empty collections bool
to False. This makes Truth testing easier.
bool([])
False
bool('')
False
bool({})
False
bool([1])
True
bool([[]])
True
bool(' ')
True
any empty collection, string, or 0 always bools to False.
--
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Thank you both for all the help. Your suggestions have helped clean up
a bunch of my code.
Thanks!
Matt
--
http://mail.python.org/mailman/listinfo/python-list
Re: overriding __getitem__ for a subclass of dict
On Nov 16, 2:35 am, Carl Banks pavlovevide...@gmail.com wrote: On Nov 15, 2:52 pm, Steve Howell showel...@yahoo.com wrote: Does anybody have any links that points to the rationale for ignoring instance definitions of __getitem__ when new-style classes are involved? I assume it has something to do with performance or protecting us from our own mistakes? Not important enough to justify complexity of implementation. I doubt they would have left if out of new-style classes if it had been straightforward to implement (if for no other reason than to retain backwards compatibility), but it wasn't. The way attribute lookups work meant it would have required all kinds of double lookups and edge cases. Some regarded it as dubious to begin with. And it's easily worked around by simply having __getitem__ call another method, as you've seen. Given all this it made better sense to just leave it out of new-style classes. Actually, the __getitem__ workaround that I proposed earlier only works on subclasses of dict, not dict themselves. So given a pure dictionary object, it is impossible to hook into attribute lookups after instantiation in debugging/tracing code. I know it's not a super common thing to do, but it is a legitimate use case from my perspective. But I understand the tradeoffs. They seem kind of 20th century to me, but with Moore's Law declining and all, maybe it's a bad time to bring up the flexibility trumps performance argument. ;) The backward compatibility argument also seems a little dubious, because if anybody *had* put __getitem__ on a dictionary instance before, it would have already been broken code, and if they hadn't done it, there would be no semantic change, just a performance hit, albeit a pervasive one. Unfortunately not all such decisions and justifications are collected in a tidy place. Yep, that's why I was asking here. I figured somebody might remember a thread on python-dev where this was discussed, or something like that. -- http://mail.python.org/mailman/listinfo/python-list
Re: Language mavens: Is there a programming with if then else ENDIF syntax?
Nobody wrote:
On Mon, 16 Nov 2009 08:54:28 -0800, Steve Ferg wrote:
For a long time I've wondered why languages still use blocks
(delimited by do/end, begin/end, { } , etc.) in ifThenElse statements.
I've often thought that a language with this kind of block-free syntax
would be nice and intuitive:
if condition then
do stuff
elif condition then
do stuff
else
do stuff
endif
Note that you do not need block delimiters.
Does anybody know a language with this kind of syntax for
ifThenElseEndif?
BBC BASIC V had if/then/else/endif (it didn't have elif).
I forgot about that one. :-(
I used to do this in order if I wanted to avoid a lot of indentation:
CASE TRUE OF
WHEN condition
do something
WHEN condition
do something
OTHERWISE
do something
ENDCASE
make has if/else/else/endif (it doesn't have a dedicated elif, but
else if ... behaves like elif rather than starting a nested if).
Is there any particular reason why this might be a *bad* language-
design idea?
Blocks can be useful for other reasons (e.g. limiting variable scope), so
if you already have them, you don't need to provide dedicated blocks
for control constructs.
--
http://mail.python.org/mailman/listinfo/python-list
Re: A terminators' club for clp
On Nov 14, 12:08 pm, r rt8...@gmail.com wrote: On Nov 14, 7:28 am, gil_johnson x7-g5w...@earthlink.net wrote: Actually there is a rank this post (gotta be careful with that verbage!) AND a report this post as spam. Of course it only exists in GG's and not Usenet. I *do* know that the star system is used quite frequently, but i doubt anyone bothers to use the report as spam link since it seems have no effect whatsoever. Heh. I should look around more before posting. It does prove your point, though. The 'spam' button is ubiquitous, but so seldom used it's forgotten. Actually, my enthusiasm for my idea faded with a little thought. It is an extra effort to open spam to get to the 'spam' button, and sends the message to the spammer that people are, indeed opening their junk. I'd use it if I opened a message with a deceptive subject. Gil -- http://mail.python.org/mailman/listinfo/python-list
Web servers
Any suggestions on using Python to connect to Web servers (e.g. to access financial time series data)? --V. Stokes -- http://mail.python.org/mailman/listinfo/python-list
Re: Language mavens: Is there a programming with if then else ENDIF syntax?
On Mon, Nov 16, 2009 at 8:54 AM, Steve Ferg
steve.ferg.bitbuc...@gmail.com wrote:
This is a question for the language mavens that I know hang out here.
It is not Python related, except that recent comparisons of Python to
Google's new Go language brought it to mind.
NOTE that this is *not* a suggestion to change Python. I like Python
just the way it is. I'm just curious about language design.
For a long time I've wondered why languages still use blocks
(delimited by do/end, begin/end, { } , etc.) in ifThenElse statements.
I've often thought that a language with this kind of block-free syntax
would be nice and intuitive:
if condition then
do stuff
elif condition then
do stuff
else
do stuff
endif
Note that you do not need block delimiters.
snip
Does anybody know a language with this kind of syntax for
ifThenElseEndif?
Ruby:
if count 10
puts Try again
elsif tries == 3
puts You lose
else
puts Enter a number
end
Cheers,
Chris
--
http://blog.rebertia.com
--
http://mail.python.org/mailman/listinfo/python-list
Re: Web servers
On Mon, Nov 16, 2009 at 11:17 AM, Virgil Stokes v...@it.uu.se wrote: Any suggestions on using Python to connect to Web servers (e.g. to access financial time series data)? In what format? Using what protocol? (*Insert other basic questions that need answering in order to answer your question here*) Cheers, Chris -- http://blog.rebertia.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Changing the current directory (full post)
On Nov 16, 2:35 am, Gabriel Genellina gagsl-...@yahoo.com.ar wrote: En Sun, 15 Nov 2009 09:04:06 -0300, vsoler vicente.so...@gmail.com escribió: Ever since I installed my Python 2.6 interpreter (I use IDLE), I've been saving my *.py files in the C:\Program Files\Python26 directory, which is the default directory for such files in my system. However, I have realised that the above is not the best practice. Therefore I created the C:\Program Files\Python26\test directory and I want it to be my default directory for saving *.py files, importing modules, etc. This is *not* a good place either. Non-privileged users should not have write permission in the C:\Program Files directory. I'd like to do something like the DOS equivalent of CD test but I do not know kow to do it. I am currently doing something really awful: I open a *.py file in the test subdirectory, I run it with the F5 key and it works! but I am doing really something stupid. it works! What's the problem then? How should I proceed, if I want to proceed properly? Sorry but I don't even see your problem. You can save your .py files anywhere you like... -- Gabriel Genellina Gabriel, When I enter IDLE, I'd like to say at the prompt: my current directory is... ...test and then be able to run a module in that directory. This is what my problem is!!! Thank you if you can help -- http://mail.python.org/mailman/listinfo/python-list
Re: Changing the current directory (full post)
On Mon, Nov 16, 2009 at 11:36 AM, vsoler vicente.so...@gmail.com wrote: On Nov 16, 2:35 am, Gabriel Genellina gagsl-...@yahoo.com.ar wrote: En Sun, 15 Nov 2009 09:04:06 -0300, vsoler vicente.so...@gmail.com escribió: Ever since I installed my Python 2.6 interpreter (I use IDLE), I've been saving my *.py files in the C:\Program Files\Python26 directory, which is the default directory for such files in my system. However, I have realised that the above is not the best practice. Therefore I created the C:\Program Files\Python26\test directory and I want it to be my default directory for saving *.py files, importing modules, etc. This is *not* a good place either. Non-privileged users should not have write permission in the C:\Program Files directory. I'd like to do something like the DOS equivalent of CD test but I do not know kow to do it. I am currently doing something really awful: I open a *.py file in the test subdirectory, I run it with the F5 key and it works! but I am doing really something stupid. it works! What's the problem then? How should I proceed, if I want to proceed properly? Sorry but I don't even see your problem. You can save your .py files anywhere you like... -- Gabriel Genellina Gabriel, When I enter IDLE, I'd like to say at the prompt: my current directory is... ...test and then be able to run a module in that directory. This is what my problem is!!! 1. File - Open 2. Navigate to file and choose it 3. Press F5 Cheers, Chris -- http://blog.rebertia.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Changing the current directory (full post)
On Nov 16, 8:45 pm, Chris Rebert c...@rebertia.com wrote: On Mon, Nov 16, 2009 at 11:36 AM, vsoler vicente.so...@gmail.com wrote: On Nov 16, 2:35 am, Gabriel Genellina gagsl-...@yahoo.com.ar wrote: En Sun, 15 Nov 2009 09:04:06 -0300, vsoler vicente.so...@gmail.com escribió: Ever since I installed my Python 2.6 interpreter (I use IDLE), I've been saving my *.py files in the C:\Program Files\Python26 directory, which is the default directory for such files in my system. However, I have realised that the above is not the best practice. Therefore I created the C:\Program Files\Python26\test directory and I want it to be my default directory for saving *.py files, importing modules, etc. This is *not* a good place either. Non-privileged users should not have write permission in the C:\Program Files directory. I'd like to do something like the DOS equivalent of CD test but I do not know kow to do it. I am currently doing something really awful: I open a *.py file in the test subdirectory, I run it with the F5 key and it works! but I am doing really something stupid. it works! What's the problem then? How should I proceed, if I want to proceed properly? Sorry but I don't even see your problem. You can save your .py files anywhere you like... -- Gabriel Genellina Gabriel, When I enter IDLE, I'd like to say at the prompt: my current directory is... ...test and then be able to run a module in that directory. This is what my problem is!!! 1. File - Open 2. Navigate to file and choose it 3. Press F5 Cheers, Chris --http://blog.rebertia.com Say that you wanted to import a file in the test directory after just entering IDLE. How would you do it? -- http://mail.python.org/mailman/listinfo/python-list
Re: Changing the current directory (full post)
On Mon, 16 Nov 2009 11:56:49 -0800, vsoler vicente.so...@gmail.com wrote: On Nov 16, 8:45 pm, Chris Rebert c...@rebertia.com wrote: On Mon, Nov 16, 2009 at 11:36 AM, vsoler vicente.so...@gmail.com wrote: On Nov 16, 2:35 am, Gabriel Genellina gagsl-...@yahoo.com.ar wrote: En Sun, 15 Nov 2009 09:04:06 -0300, vsoler vicente.so...@gmail.com escribió: Ever since I installed my Python 2.6 interpreter (I use IDLE), I've been saving my *.py files in the C:\Program Files\Python26 directory, which is the default directory for such files in my system. However, I have realised that the above is not the best practice. Therefore I created the C:\Program Files\Python26\test directory and I want it to be my default directory for saving *.py files, importing modules, etc. This is *not* a good place either. Non-privileged users should not have write permission in the C:\Program Files directory. I'd like to do something like the DOS equivalent of CD test but I do not know kow to do it. I am currently doing something really awful: I open a *.py file in the test subdirectory, I run it with the F5 key and it works! but I am doing really something stupid. it works! What's the problem then? How should I proceed, if I want to proceed properly? Sorry but I don't even see your problem. You can save your .py files anywhere you like... -- Gabriel Genellina Gabriel, When I enter IDLE, I'd like to say at the prompt: my current directory is... ...test and then be able to run a module in that directory. This is what my problem is!!! 1. File - Open 2. Navigate to file and choose it 3. Press F5 Cheers, Chris --http://blog.rebertia.com Say that you wanted to import a file in the test directory after just entering IDLE. How would you do it? http://docs.python.org/library/os.html#os.chdir and http://docs.python.org/library/sys.html#sys.path may be able to help you... -- Rami Chowdhury Never attribute to malice that which can be attributed to stupidity -- Hanlon's Razor 408-597-7068 (US) / 07875-841-046 (UK) / 0189-245544 (BD) -- http://mail.python.org/mailman/listinfo/python-list
Re: Changing the current directory (full post)
On Mon, Nov 16, 2009 at 11:56 AM, vsoler vicente.so...@gmail.com wrote: On Nov 16, 8:45 pm, Chris Rebert c...@rebertia.com wrote: On Mon, Nov 16, 2009 at 11:36 AM, vsoler vicente.so...@gmail.com wrote: On Nov 16, 2:35 am, Gabriel Genellina gagsl-...@yahoo.com.ar wrote: En Sun, 15 Nov 2009 09:04:06 -0300, vsoler vicente.so...@gmail.com escribió: Ever since I installed my Python 2.6 interpreter (I use IDLE), I've been saving my *.py files in the C:\Program Files\Python26 directory, which is the default directory for such files in my system. However, I have realised that the above is not the best practice. Therefore I created the C:\Program Files\Python26\test directory and I want it to be my default directory for saving *.py files, importing modules, etc. This is *not* a good place either. Non-privileged users should not have write permission in the C:\Program Files directory. I'd like to do something like the DOS equivalent of CD test but I do not know kow to do it. I am currently doing something really awful: I open a *.py file in the test subdirectory, I run it with the F5 key and it works! but I am doing really something stupid. it works! What's the problem then? How should I proceed, if I want to proceed properly? Sorry but I don't even see your problem. You can save your .py files anywhere you like... When I enter IDLE, I'd like to say at the prompt: my current directory is... ...test and then be able to run a module in that directory. This is what my problem is!!! 1. File - Open 2. Navigate to file and choose it 3. Press F5 Say that you wanted to import a file in the test directory after just entering IDLE. How would you do it? import sys sys.path.insert(0, C:/path/to/test/dir/here) import something_in_test_dir Cheers, Chris -- http://blog.rebertia.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Language mavens: Is there a programming with if then else ENDIF syntax?
On Nov 16, 10:54 am, Steve Ferg steve.ferg.bitbuc...@gmail.com wrote: I've often thought that a language with this kind of block-free syntax would be nice and intuitive: if condition then do stuff elif condition then do stuff else do stuff endif WHY? Python's syntax is by far the most elegant of all, no need to show the end of a block. Python is the smartest kid on the block. And are you saying you would rather type then instead of : and endif instead of \n? No thanks! -- http://mail.python.org/mailman/listinfo/python-list
Re: Web servers
Virgil Stokes wrote: div class=moz-text-flowed style=font-family: -moz-fixedAny suggestions on using Python to connect to Web servers (e.g. to access financial time series data)? --V. Stokes You can open a web page for reading with urllib2 module. You can parse html with beautiful soup, or if it's clean xhtml, with the xml module. But parsing raw html is error prone, and subject to change as the web designer reorganizes things. So many web servers also have a protocol intended for data (as opposed to intended for a browser). This is specific to each service, however. If you want to get started in your reading, you could google for web services, which is one approach using SOAP WSDL. Note also that most servers have restrictions on the data you access this way. They may or may not be enforceable, but if you access a lot of data from a server, you may be too big a drain on its resources, if it's configured for browser access only. DaveA -- http://mail.python.org/mailman/listinfo/python-list
directory wildcard
List, I try to assign value to force_mcs sitting in a wildcard subdirectory /sys/kernel/debug/ieee80211/phy*, but python does not work for that such as: os.system(echo %i /sys/kernel/debug/ieee80211/phy*/iwlagn/data/force_mcs % mcs) Any right way to do it? Thanks. --henry -- http://mail.python.org/mailman/listinfo/python-list
Re: Language mavens: Is there a programming with if then else ENDIF syntax?
In article ff92db5b-9cb0-4a72-b339-2c5ac02fb...@p36g2000vbn.googlegroups.com, Steve Ferg steve.ferg.bitbuc...@gmail.com wrote: I've often thought that a language with this kind of block-free syntax would be nice and intuitive: if condition then do stuff elif condition then do stuff else do stuff endif Note that you do not need block delimiters. then, else, and endif *are* the block delimiters -- -Ed Falk, f...@despams.r.us.com http://thespamdiaries.blogspot.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Language mavens: Is there a programming with if then else ENDIF syntax?
On 2009-11-16 14:40 PM, Edward A. Falk wrote:
In articleff92db5b-9cb0-4a72-b339-2c5ac02fb...@p36g2000vbn.googlegroups.com,
Steve Fergsteve.ferg.bitbuc...@gmail.com wrote:
I've often thought that a language with this kind of block-free syntax
would be nice and intuitive:
ifcondition then
do stuff
elifcondition then
do stuff
else
do stuff
endif
Note that you do not need block delimiters.
then, else, and endif *are* the block delimiters
I think he meant that you don't need *extra* block delimiters or generic block
delimiters like {}.
--
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
--
http://mail.python.org/mailman/listinfo/python-list
Re: directory wildcard
hong zhang schrieb: List, I try to assign value to force_mcs sitting in a wildcard subdirectory /sys/kernel/debug/ieee80211/phy*, but python does not work for that such as: os.system(echo %i /sys/kernel/debug/ieee80211/phy*/iwlagn/data/force_mcs % mcs) Any right way to do it? Don't use os system. Use subprocess. Which incidentially is mentioned in the docs for os.system: http://docs.python.org/library/os.html#os.system Then you can pass the use_shell=True parameter - which should work in your case. Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: directory wildcard
On Nov 16, 3:33 pm, hong zhang henryzhan...@yahoo.com wrote:
List,
I try to assign value to force_mcs sitting in a wildcard subdirectory
/sys/kernel/debug/ieee80211/phy*, but python does not work for that such as:
os.system(echo %i /sys/kernel/debug/ieee80211/phy*/iwlagn/data/force_mcs
% mcs)
Any right way to do it?
Thanks.
--henry
I'd ditch the echo business altogether. 2.x. Not tested.
import glob
mcs = get_mcs_from_somewhere()
for i in glob.glob('/sys/kernel/debug/ieee80211/phy*/iwlagn/data/
force_mcs'):
with open(i, 'w') as f:
print f, mcs
Thanks,
Jeff
mcjeff.blogspot.com
--
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Re: Redirect stdout to a buffer [Errno 9]
On Nov 16, 7:21 pm, Gabriel Genellina gagsl-...@yahoo.com.ar
wrote:
En Mon, 16 Nov 2009 14:17:52 -0300, Ecir Hana ecir.h...@gmail.com
escribió:
I'm trying to write a simple Win32 app, which may run some Python
scripts. Since it is a Windows GUI app, I would like to redirect all
output (Python print, C printf, fprinf stderr, ...) to a text area
inside the app. In other words, I'm trying to log all the output from
the app (C, Python) to a window. So far, this works for C printf():
[...]
PS: Maybe I'm doind something wrong, but SetStdHandle() does not work
at all
This worked for me:
#include windows.h
#include Python.h
int main()
{
HANDLE hReadPipe, hWritePipe;
DWORD nr, nw;
char buffer[100];
CreatePipe(
hReadPipe,
hWritePipe,
NULL,
1024);
SetStdHandle(STD_OUTPUT_HANDLE, hWritePipe);
Py_Initialize();
PyRun_SimpleString(print 'from Python');
Py_Finalize();
puts(from C\n);
CloseHandle(hWritePipe);
ReadFile(hReadPipe, buffer, 19, nr, NULL);
CloseHandle(hReadPipe);
WriteFile(GetStdHandle(STD_ERROR_HANDLE), buffer, nr, nw, NULL);
}
Also, maybe this matters: it's on WinXP, Python 2.6 and MinGW GCC.
I'm using Visual Studio 2008 Express Edition.
--
Gabriel Genellina
Hi,
thanks for the reply!
However, please, could you tell me how many bytes it read here:
ReadFile(hReadPipe, buffer, 19, nr, NULL);
because for me, it has read 0. When I run your code, it prints from
both C and Python, but it prints straight to the console, not to the
buffer. Could you also please try to add:
WriteFile(GetStdHandle(STD_ERROR_HANDLE), \n, 5, nw, NULL);
before:
WriteFile(GetStdHandle(STD_ERROR_HANDLE), buffer, nr, nw, NULL);
Does it print before from Python and from C for you?
Because for me it comes afterwards (as nr is 0)...
--
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Re: Changing the current directory (full post)
Chris Rebert wrote: On Mon, Nov 16, 2009 at 11:56 AM, vsoler vicente.so...@gmail.com wrote: On Nov 16, 8:45 pm, Chris Rebert c...@rebertia.com wrote: On Mon, Nov 16, 2009 at 11:36 AM, vsoler vicente.so...@gmail.com wrote: On Nov 16, 2:35 am, Gabriel Genellina gagsl-...@yahoo.com.ar wrote: En Sun, 15 Nov 2009 09:04:06 -0300, vsoler vicente.so...@gmail.com escribió: Ever since I installed my Python 2.6 interpreter (I use IDLE), I've been saving my *.py files in the C:\Program Files\Python26 directory, which is the default directory for such files in my system. However, I have realised that the above is not the best practice. Therefore I created the C:\Program Files\Python26\test directory and I want it to be my default directory for saving *.py files, importing modules, etc. This is *not* a good place either. Non-privileged users should not have write permission in the C:\Program Files directory. I'd like to do something like the DOS equivalent of CD test but I do not know kow to do it. I am currently doing something really awful: I open a *.py file in the test subdirectory, I run it with the F5 key and it works! but I am doing really something stupid. it works! What's the problem then? How should I proceed, if I want to proceed properly? Sorry but I don't even see your problem. You can save your .py files anywhere you like... When I enter IDLE, I'd like to say at the prompt: my current directory is... ...test and then be able to run a module in that directory. This is what my problem is!!! 1. File - Open 2. Navigate to file and choose it 3. Press F5 Say that you wanted to import a file in the test directory after just entering IDLE. How would you do it? import sys sys.path.insert(0, C:/path/to/test/dir/here) import something_in_test_dir Cheers, Chris -- http://blog.rebertia.com Change directory to the test-directory Then run idle -- http://mail.python.org/mailman/listinfo/python-list
Re: IDE for python
Jonathan Hartley tart...@tartley.com writes: I'd like to offer the group the anecdote of the great Resolver IDE migration. […] It's great to see something refreshing and new — data beyond a single person's subjective experience! — come out of a topic that looked like it was just going to re-hash the same tired topic. Thank you. -- \ “What I resent is that the range of your vision should be the | `\ limit of my action.” —Henry James | _o__) | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
Re: directory wildcard
I try to assign value to force_mcs sitting in a wildcard
subdirectory /sys/kernel/debug/ieee80211/phy*, but python does
not work for that such as:
os.system(echo %i
/sys/kernel/debug/ieee80211/phy*/iwlagn/data/force_mcs % mcs)
Any right way to do it?
I'm not sure your code works if there's more than one phy*
directory in that folder anyways since piping usually only
works for a single destination. Though I'd imagine this is only
a problem for folks that have more than one 802.11 card in their
machine (which I've done...a useless on-board and a PCMCIA on an
older laptop).
I'd use python's built-in glob module to do something like
from glob import glob
def set_force_mcs(mcs):
for fname in glob('/sys/kernel/debug/'
'ieee80211/phy*/iwlagn/data/force_mcs'):
f = open(fname, 'w')
f.write('%i\n' % mcs)
f.close()
#the following should all work
set_force_mcs(True)
set_force_mcs(False)
set_force_mcs(1)
set_force_mcs(0)
(I broke the for/glob line intentionally in a way that python
transparently restores in case mailers munged them between here
in there...normally, I'd just use a single string parameter for
glob() instead of line-breaking it if it fit in 80 chars)
If you're using a more recent version of python that has the
with command (I think it was added in 2.6, and available from
2.5's future), it could be tidied to
with open(fname, 'w') as f:
f.write('%i\n' % mcs)
-tkc
--
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mySQL access speed
Hello, I have some programs doing a lot sql IO in some mySQL databases. This works very fine and the DBAPI is quite simple to understand. Now I came to the point where I had to insert millions of lines into a table. My first aproach was to insert the data using executemany(). That's not bad and fairly simple to use. But it isn't very fast. For executemany I have some hundred thousend lines in a list of tuples. I joined() these lines to form an insert into table values () statement and blew it into the mysql cmdline client via os.popen(). This was 60(!) times faster and loaded my table in seconds! Is the mySQL module so slow ? Any ideas to have the mySQL module working faster ? The popen() way seems quite clumsy and not very pythonic for me, Greetings Hans -- http://mail.python.org/mailman/listinfo/python-list
Re: Language mavens: Is there a programming with if then else ENDIF syntax?
On Nov 16, 10:54 am, Steve Ferg steve.ferg.bitbuc...@gmail.com
wrote:
This is a question for the language mavens that I know hang out here.
It is not Python related, except that recent comparisons of Python to
Google's new Go language brought it to mind.
NOTE that this is *not* a suggestion to change Python. I like Python
just the way it is. I'm just curious about language design.
For a long time I've wondered why languages still use blocks
(delimited by do/end, begin/end, { } , etc.) in ifThenElse statements.
I've often thought that a language with this kind of block-free syntax
would be nice and intuitive:
if condition then
do stuff
elif condition then
do stuff
else
do stuff
endif
Note that you do not need block delimiters.
Obviously, you could make a more Pythonesque syntax by using a colon
rather then then for the condition terminator. You could make it
more PL/I-like by using do, etc.
You can write shell scripts using if ... fi, but other than that I
don't recall a language with this kind of syntax.
Does anybody know a language with this kind of syntax for
ifThenElseEndif?
Is there any particular reason why this might be a *bad* language-
design idea?
Fortran95. You can even label the IF...END IF structure -- handy for
immense blocks.
This is not a criticism of Python (or of Fortran).
--
http://mail.python.org/mailman/listinfo/python-list
Re: directory wildcard
--- On Mon, 11/16/09, Jeff McNeil j...@jmcneil.net wrote:
From: Jeff McNeil j...@jmcneil.net
Subject: Re: directory wildcard
To: python-list@python.org
Date: Monday, November 16, 2009, 3:01 PM
On Nov 16, 3:33 pm, hong zhang
henryzhan...@yahoo.com
wrote:
List,
I try to assign value to force_mcs sitting in a
wildcard subdirectory /sys/kernel/debug/ieee80211/phy*, but
python does not work for that such as:
os.system(echo %i
/sys/kernel/debug/ieee80211/phy*/iwlagn/data/force_mcs %
mcs)
Any right way to do it?
Thanks.
--henry
I'd ditch the echo business altogether. 2.x. Not tested.
import glob
mcs = get_mcs_from_somewhere()
for i in
glob.glob('/sys/kernel/debug/ieee80211/phy*/iwlagn/data/
force_mcs'):
with open(i, 'w') as f:
print f, mcs
This assigns decimal value, how can I assign Hex here to mcs?
--
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Re: mySQL access speed
... But it isn't very fast. For executemany I have some hundred thousend lines in a list of tuples. I joined() these lines to form an insert into table values () statement and blew it into the mysql cmdline client via os.popen(). This was 60(!) times faster and loaded my table in seconds! Is the mySQL module so slow ? No. The fact that each statement is atomic makes it slow. Try the multiple queries, but precede them with a SET AUTOCOMMIT=0 statement or use a transaction. You will probably see a tremendous speed increase. When you combine all the queries into one statement, you are effectively doing the same. Best regards, Dikkie. -- http://mail.python.org/mailman/listinfo/python-list
faster than list.extend()
Hi, all. I want to improve speed of following simple function. Any suggestion? ** def triple(inputlist): results = [] for x in inputlist: results.extend([x,x,x]) return results ** Thank you in advance, Hyunchul -- http://mail.python.org/mailman/listinfo/python-list
Re: Language mavens: Is there a programming with if then else ENDIF syntax?
r wrote: On Nov 16, 10:54 am, Steve Ferg steve.ferg.bitbuc...@gmail.com wrote: I've often thought that a language with this kind of block-free syntax would be nice and intuitive: if condition then do stuff elif condition then do stuff else do stuff endif WHY? Python's syntax is by far the most elegant of all, no need to show the end of a block. Python is the smartest kid on the block. And are you saying you would rather type then instead of : and endif instead of \n? No thanks! You clipped out the part where he explicitly said it was not a suggestion to change Python. -- Erik Max Francis m...@alcyone.com http://www.alcyone.com/max/ San Jose, CA, USA 37 18 N 121 57 W AIM/Y!M/Skype erikmaxfrancis Mona Lisa / Come to discover / I am your daughter -- Lamya -- http://mail.python.org/mailman/listinfo/python-list
Re: Language mavens: Is there a programming with if then else ENDIF syntax?
Steve Ferg wrote: I've often thought that a language with this kind of block-free syntax would be nice and intuitive: if condition then do stuff elif condition then do stuff else do stuff endif Note that you do not need block delimiters. Obviously, you could make a more Pythonesque syntax by using a colon rather then then for the condition terminator. You could make it more PL/I-like by using do, etc. You can write shell scripts using if ... fi, but other than that I don't recall a language with this kind of syntax. It's the same syntax, with `fi` written instead of `endif` -- not sure why the difference in keyword is that big of a deal to you. As others have pointed out, either way, there are quite a few languages that use this type of syntax. -- Erik Max Francis m...@alcyone.com http://www.alcyone.com/max/ San Jose, CA, USA 37 18 N 121 57 W AIM/Y!M/Skype erikmaxfrancis Mona Lisa / Come to discover / I am your daughter -- Lamya -- http://mail.python.org/mailman/listinfo/python-list
Re: faster than list.extend()
On Mon, Nov 16, 2009 at 2:30 PM, Hyunchul Kim hyunchul.mail...@gmail.com wrote: Hi, all. I want to improve speed of following simple function. Any suggestion? ** def triple(inputlist): results = [] for x in inputlist: results.extend([x,x,x]) return results ** You'd probably be better off calling .append() 3 times instead of .extend() as it would avoid the creation of all those intermediate 3-element lists. Cheers, Chris -- http://blog.rebertia.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Changing the current directory (full post)
En Mon, 16 Nov 2009 18:10:51 -0300, Dave Angel da...@ieee.org escribió: Chris Rebert wrote: On Mon, Nov 16, 2009 at 11:56 AM, vsoler vicente.so...@gmail.com wrote: When I enter IDLE, I'd like to say at the prompt: my current directory is... ...test and then be able to run a module in that directory. This is what my problem is!!! Change directory to the test-directory Then run idle Or, modify the Initial Directory in the menu shortcut that you use to start IDLE (right click, Properties). Or create another shortcut in your desktop using your desired initial directory. -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
