Jython 2.5 Beta1 Released!
On behalf of the Jython development team, I'm pleased to announce that Jython 2.5b1 is available for download: http://downloads.sourceforge.net/jython/jython_installer-2.5b1.jar. See the installation instructions here: http://www.jython.org/Project/installation.html. Jython 2.5 Beta1 continues a code cooling period where the number of new features should significantly slow as we concentrate on solidifying Jython 2.5 for an eventual release. I would guess that we will put out about two more betas before we start pushing out release candidates, hopefully in February. This is a beta release so be careful. -Frank -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations.html
Open Technology Group, Inc. announces Django GeoDjango MVC Framework Training
Morrisville, NC (PRWEB) January 9, 2009 -- Open Technology Group, Inc. announces Django GeoDjango MVC Framework Training The Open Technology Group (OTG), a leader in the development and delivery of training solutions centered about Open Source technologies, released the latest in its set of Open Source Django training (http://www.otg-nc.com/django-training) courses. A powerful Model-View-Controller (MVC) framework written in Python, Django provides web developers with an intuitive framework to develop web-based applications. Programmers attending our Django training will learn how to develop, deploy, maintain, and administer Django applications, said Chander Ganesan, President, This hands-on course teaches web developers all they need to know to leverage the powerful features and functionality of the Django Framework. Students attending this training will learn - from start to finish - how to develop web applications using Django through a series of instructor-led lectures and hands on exercises, culminating in a complete, working web application. OTG also announced a Django training course dedicated to Geospatial Professionals, Leveraging GeoDjango (http://www.otg-nc.com/geodjango-training). GeoDjango builds upon the Django MVC framework by adding integrated support for Geospatial databases (including PostGIS and Oracle Spatial), as well as the GEOS and GDAL API's. This 2 day course teaches students how to use PostgreSQL, PostGIS, and GeoDjango to build powerful spatially enabled applications using the GeoDjango Django framework. OTG also provides training for Python, PostGIS, OpenLayers, JavaScript/AJAX, MySQL, and PostgreSQL - technologies that complement both Django and GeoDjango. Both new classes are available today for both public enrollment and customized, affordable, on-site delivery to small groups (3 or more students) worldwide. About Open Technology Group, Inc. Founded in 2004 and headquartered in Morrisville, NC, the Open Technology Group, Inc. (OTG) has established itself as the leading provider of training solutions centered about Open Source software and solutions. With its comprehensive library of in-house developed intellectual property, OTG is able to deliver comprehensive, customized, and structured training covering a wide range of software solutions. The Open Technology Group offers affordable customized on-site technology training worldwide, as well as public-enrollment courses delivered in over 10 locations, nationwide. For more information, and a complete course catalog, visit us online at http://www.otg-nc.com/python-training, or contact us at 877-258-8987 -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations.html
[ANNOUNCE] MyHDL 0.6 released
I'm happy to announce the release of MyHDL 0.6. MyHDL is a Python package for using Python as a hardware description language. The highlight of this release is conversion to VHDL, in addition to the existing Verilog capability. Furthermore, the convertible subset has been broadened substantially beyond synthesizable logic, to support test bench conversion. For a complete overview, see: http://www.myhdl.org/doku.php/overview To check whether MyHDL can be useful to you, please read: http://www.myhdl.org/doku.php/why To find out the details of what's new in this release: http://www.myhdl.org/doc/0.6/whatsnew/0.6.html You can download the release from SourceForge: http://sourceforge.net/project/showfiles.php?group_id=91207 Best regards, Jan Decaluwe -- Jan Decaluwe - Resources bvba - http://www.jandecaluwe.com Python as a hardware description language: http://www.myhdl.org -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations.html
Re: BadZipfile file is not a zip file
On Thu, 08 Jan 2009 16:47:39 -0800, webcomm wrote:
The error...
...
BadZipfile: File is not a zip file
When I look at data.zip in Windows, it appears to be a valid zip file.
I am able to uncompress it in Windows XP, and can also uncompress it
with 7-Zip. It looks like zipfile is not able to read a table of
contents in the zip file. That's not a concept I'm familiar with.
No, ZipFile can read table of contents:
Help on method printdir in module zipfile:
printdir(self) unbound zipfile.ZipFile method
Print a table of contents for the zip file.
In my experience, zip files originating from Windows sometimes have
garbage at the end of the file. WinZip just ignores the garbage, but
other tools sometimes don't -- if I recall correctly, Linux unzip
successfully unzips the file but then complains that the file was
corrupt. It's possible that you're running into a similar problem.
data.zip is created in this script...
decoded = base64.b64decode(datum)
f = open('data.zip', 'wb')
f.write(decoded)
f.close()
file = zipfile.ZipFile('data.zip', r)
datum is a base64 encoded zip file. Again, I am able to open data.zip
as if it's a valid zip file. Maybe there is something wrong with the
approach I've taken to writing the data to data.zip? I'm not sure if it
matters, but the zipped data is Unicode.
The full signature of ZipFile is:
ZipFile(file, mode=r, compression=ZIP_STORED, allowZip64=True)
Try passing compression=zipfile.ZIP_DEFLATED and/or allowZip64=False and
see if that makes any difference.
The zip format does support alternative compression methods, it's
possible that this particular file uses a different sort of compression
which Python doesn't deal with.
What would cause a zip file to not have a table of contents?
What makes you think it doesn't have one?
--
Steven
--
http://mail.python.org/mailman/listinfo/python-list
Re: ulimit stack size and python threads
Always crashing because I asked the OS to please not allow a process to grow too big is what I call overloading the meaning of ulimit -s. Please trust that there is no explicit code in the Python interpreter that tests whether the stack size is 4GB, and then produces an explicit crash. It's quite surprising. Not to mention the poor error message. AFAICT, you didn't even *report* yet what the error message is, so I don't know whether it is poor. Regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
Re: ulimit stack size and python threads
I see. I should be blaming the default behavior of pthreads. You shouldn't blame anybody. Instead, you should sit down and study the problem in detail, until you fully understand it. Then you should start contributing fixes. Never ever should you spread blame. Regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
Encrypted Logging in python
I was wondering if there is a mechanism to encrypt logging automatically in python. The issue is as follows: (a) An application (after py2exe) will go as executable and there is no need for the user to know that it is written in python. If an exception occurs and it is logged, then the user can understand it is written in python. (b) A security threat. If an exception occurs, the code is seen by the user - and possibly be misused. Base64 encoding somewhat helps - which is supported by logging module - but even that is not very secure. If there can be an option - wherein we send in the password and the logging is encrypted - it might be better. I would have loved to provide the code, but I am completely tied up at the moment and wont be able to help for another month. -- http://mail.python.org/mailman/listinfo/python-list
Re: threading in PyQt vs threading in standard library
On Fri, 9 Jan 2009 15:15:28 +0800, Steven Woody narkewo...@gmail.com wrote: Hi, I am considering using PyQt for GUI programs, and I notices that both of them include threading supports, so which one should I pick up? Similar also applies 'socket'. I'd recommend using the PyQt versions of both. A significant advantage of PyQt's sockets is that they are integrated with the event loop. This means you don't need threads to handle networking. Phil -- http://mail.python.org/mailman/listinfo/python-list
Re: BadZipfile file is not a zip file
What would cause a zip file to not have a table of contents? AFAICT, _EndRecData is failing to find the end of zipfile structure in the file. You might want debug through it to see where it looks, and how it decides that this structure is not present in the file. Towards 22 bytes before the end of the file, the bytes PK\005\006 should appear. If they don't appear, you don't have a zipfile. If they appear, but elsewhere towards the end of the file, there might be a bug in the zip file module (or, more likely, the zip file uses an optional zip feature which the module doesn't implement). Regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
Re: Replying to list messages
On Thu, 08 Jan 2009 10:42:13 -0800, Paul McNett wrote: Ben Finney wrote: Paul McNett p...@ulmcnett.com writes: But arguing about this here isn't going to change anything: opinions differ just like tabs/spaces and bottom-post/top-post. In cases like this, one side can simply be wrong :-) Best of luck getting your programs behaving as you want them to! BTW, I agree with you that in an ideal, pure world mailing lists wouldn't munge the reply-to field, but when 80% of the people use email clients that don't support reply-list, the practical thing to do as a list admin that wants to avoid having to explain over and over again that your client software is broken is to simply swallow some pride and munge the reply-to. Now, 99% of the users are happy, and the remaining 1% are elite enough to understand how to get around any problems this caused. The only problem this leads to is people who hit send without checking where they are sending to are likely to be embarrassed when they send personal posts to the entire mailing list. As far as I'm concerned, hitting send without looking to see who you are sending to is akin to turning into a busy road without looking to see if there are any cars coming: any accident that happens is YOUR fault, not the fault of the road, car, mail client or mailing list. It boggles my brain that [insert sweeping generalisation here] the people who are most vehement about blaming the mailing list software are usually also the least understanding when (l)users click OK to dialogs without reading what the dialog says first. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: BadZipfile file is not a zip file
On Jan 9, 2:16 am, Steven D'Aprano st...@remove-this- cybersource.com.au wrote: On Thu, 08 Jan 2009 16:47:39 -0800, webcomm wrote: The error... ... BadZipfile: File is not a zip file When I look at data.zip in Windows, it appears to be a valid zip file. I am able to uncompress it in Windows XP, and can also uncompress it with 7-Zip. It looks like zipfile is not able to read a table of contents in the zip file. That's not a concept I'm familiar with. No, ZipFile can read table of contents: Help on method printdir in module zipfile: printdir(self) unbound zipfile.ZipFile method Print a table of contents for the zip file. In my experience, zip files originating from Windows sometimes have garbage at the end of the file. WinZip just ignores the garbage, but other tools sometimes don't -- if I recall correctly, Linux unzip successfully unzips the file but then complains that the file was corrupt. It's possible that you're running into a similar problem. The zipfile format is kind of brain dead, you can't tell where the end of the file is supposed to be by looking at the header. If the end of file hasn't yet been reached there could be more data. To make matters worse, somehow zip files came to have text comments simply appended to the end of them. (Probably this was for the benefit of people who would cat them to the terminal.) Anyway, if you see something that doesn't adhere to the zipfile format, you don't have any foolproof way to know if it's because the file is corrupted or if it's just an appended comment. Most zipfile readers use a heuristic to distinguish. Python's zipfile module just assumes it's corrupted. The following post from a while back gives a solution that tries to snip the comment off so that zipfile module can handle it. It might help you out. http://groups.google.com/group/comp.lang.python/msg/c2008e48368c6543 Carl Banks -- http://mail.python.org/mailman/listinfo/python-list
Re: drive a desktop app from python?
Tim Arnold wrote:
Hi, I don't even know what to google for on this one. I need to drive a
commercial desktop app (on windows xp) since the app doesn't have a batch
interface. It's intended to analyze one file at a time and display a
report.
I can get the thing to write out the report an html browser, but I have
thousands of files I need it to analyze every night.
Is there any lib or recipe(s) for doing something like this via python?
You are a little thin on details here. My only advice at this point is
to check out os.system, which is the simplest option. From there you can
move to the popen2 module for greater control, but if you are talking
about a gui app, you may run into hang-ups.
A quick recipe would be the following pretend application that
recursively descends from the current directory calling the utility
named dosapp on every file it finds that ends with jpg (what
dosapp does is left to your imagination):
import os
def doit(suffix, adir, filenames):
for afile in filenames:
if afile.endswith(suffix):
pathname = os.path.join(adir, afile)
os.system('dosapp %s' % pathname)
top = '.'
suffix = '.jpg'
os.path.walk(top, doit, suffix)
Read the docs on os.path.walk, of course.
James
--
James Stroud
UCLA-DOE Institute for Genomics and Proteomics
Box 951570
Los Angeles, CA 90095
http://www.jamesstroud.com
--
http://mail.python.org/mailman/listinfo/python-list
Re: Best practice in organize classes into modules
Steven Woody a écrit : On Fri, Jan 9, 2009 at 1:02 PM, James Mills prolo...@shortcircuit.net.au wrote: On Fri, Jan 9, 2009 at 2:57 PM, Steven Woody narkewo...@gmail.com wrote: In C++/Java, people usually put one class into one file. What's the suggestion on this topic in Python? I so much interesting this especially when exception classes also involved. Normally i group related functionality into the one module. Will that lead to too large source file size? When the case happens, then you can safely refactor the module into a package with submodules, and use the package's __init__.py to make it a facade for the submodules so the refactoring is transparent for client code. But given Python's expressivity and metaprogramming features, it's usually easy to avoid cruft and boilerplate and keep the code short. Is there a recommendation on max lines of a python source? Not really - use your own judgement, mostly. As far as I'm concerned, I start worrying about this when a module grows bigger than 1Kloc, but I seldom have this problem. -- http://mail.python.org/mailman/listinfo/python-list
Re: Best practice in organize classes into modules
On Fri, Jan 9, 2009 at 4:54 PM, Bruno Desthuilliers bruno.42.desthuilli...@websiteburo.invalid wrote: Steven Woody a écrit : On Fri, Jan 9, 2009 at 1:02 PM, James Mills prolo...@shortcircuit.net.au wrote: On Fri, Jan 9, 2009 at 2:57 PM, Steven Woody narkewo...@gmail.com wrote: In C++/Java, people usually put one class into one file. What's the suggestion on this topic in Python? I so much interesting this especially when exception classes also involved. Normally i group related functionality into the one module. Will that lead to too large source file size? When the case happens, then you can safely refactor the module into a package with submodules, and use the package's __init__.py to make it a facade for the submodules so the refactoring is transparent for client code. really a smart idea. Did you mean putting some 'import statement in __init__.py and use the old module name as the new package name? Thanks. -- http://mail.python.org/mailman/listinfo/python-list
Re: Implementing file reading in C/Python
On Fri, 09 Jan 2009 04:04:41 +0100, Johannes Bauer wrote:
I've first tried Python. Please don't beat me, it's slow as hell and
probably a horrible solution:
#!/usr/bin/python
import sys
import os
f = open(sys.argv[1], r)
Mode should be 'rb'.
filesize = os.stat(sys.argv[1])[6]
`os.path.getsize()` is a little bit more readable.
width = 1024
height = 1024
pixels = width * height
blocksize = filesize / width / height
print(Filesize : %d % (filesize)) print(Image size : %dx%d
% (width, height)) print(Bytes per Pixel: %d % (blocksize))
Why parentheses around ``print``\s argument? In Python 3 ``print`` is
a statement and not a function.
picture = { }
havepixels = 0
while True:
data = f.read(blocksize)
if len(data) = 0: break
if data:
break
is enough.
datamap = { }
for i in range(len(data)):
datamap[ord(data[i])] = datamap.get(data[i], 0) + 1
Here you are creating a list full of integers to use them as index into
`data` (twice) instead of iterating directly over the elements in
`data`. And you are calling `ord()` for *every* byte in the file
although you just need it for one value in each block. If it's possible
to write the raw PGM format this conversion wouldn't be necessary at all.
For the `datamap` a `collections.defaultdict()` might be faster.
maxchr = None
maxcnt = None
for (char, count) in datamap.items():
if (maxcnt is None) or (count maxcnt):
maxcnt = count
maxchr = char
Untested:
maxchr = max((i, c) for c, i in datamap.iteritems())[1]
most = maxchr
Why?
posx = havepixels % width
posy = havepixels / width
posx, posy = divmod(havepixels, width)
Don't know if this is faster though.
havepixels += 1
if (havepixels % 1024) == 0:
print(Progresss %s: %.1f%% % (sys.argv[1], 100.0 *
havepixels /
pixels))
picture[(posx, posy)] = most
Why are you using a dictionary as 2d array? In the C code you simply
write the values sequentially, why can't you just use a flat list and
append here?
Ciao,
Marc 'BlackJack' Rintsch
--
http://mail.python.org/mailman/listinfo/python-list
Re: Default __nonzero__ impl doesn't throw a TypeError exception
Bruno Desthuilliers a écrit : Sergey Kishchenko a écrit : (snip) #prints Ouch! f=Foo() if f: print Ouch! So, default __nonzero__ impl is to return True. Yes. It's clearly documented FWIW. To be more exact: there's no default __nonzero__. The boolean value of an object is eval'd this way: If the object is None (special cased by the interpreter AFAICT), it is false. Else if the object implements __nonzero__, it has the boolean value returned by __nonzero__. Else if the object implements __len__, it has the boolean value of its length. Else if is true. I think, this behaviour conflicts with 'Explicit is better than implicit' Why so ? It *is* explicit that the default for an object is to have a true value in a boolean context. I meant explicit because documented, of course. and 'Practicality beats purity' Quite on the contrary. From a practical POV, the default truth values of Python objects are most of the time what you practically want in a boolean context - that is, any non-None object, non-empty sequence and non-zero numeric objects are true. __nonzero__ is here for the *very few* corner cases where this is not the sensible default. statements. I think, throwing a TypeError exception would be better. It will result in more explicit code with fewer errors. As a last note wrt/ explicitness and practicality: Implementing your proposition, one would have to either put each and every boolean expression in a try/except block or explicitly define __nonzero__ for each and any class - most of the time (about 99.% I'd say) implementing it as to return True - and expect that *everybody* does so. So yes, from a purity POV, it might look more explicit. But this would certainly not be practical at all. OTHO, since boolean algebra only knows two values, it's clear that what is not false is by definition true. So having a default value (true) and a way to override it (__len__ and __nonzero__) is perhaps less pure, but really as explicit and much more practical. My 2 cents... -- http://mail.python.org/mailman/listinfo/python-list
Re: Python 2.6 fails on compiling Bug report
hm... any ideas? -- http://mail.python.org/mailman/listinfo/python-list
Re: Python 2.6 fails on compiling Bug report
On Fri, Jan 9, 2009 at 6:18 PM, googler.1.webmas...@spamgourmet.com wrote: hm... any ideas? Posting the config.log file would be a first step to give more information, David -- http://mail.python.org/mailman/listinfo/python-list
Re: Implementing file reading in C/Python
On Fri, Jan 9, 2009 at 7:15 PM, Marc 'BlackJack' Rintsch bj_...@gmx.net wrote: print(Filesize : %d % (filesize)) print(Image size : %dx%d % (width, height)) print(Bytes per Pixel: %d % (blocksize)) Why parentheses around ``print``\s argument? In Python 3 ``print`` is a statement and not a function. Not true as of 2.6+ and 3.0+ print is now a function. cheers James -- http://mail.python.org/mailman/listinfo/python-list
Re: BadZipfile file is not a zip file
On Jan 9, 7:16 pm, Steven D'Aprano st...@remove-this-
cybersource.com.au wrote:
On Thu, 08 Jan 2009 16:47:39 -0800, webcomm wrote:
The error...
...
BadZipfile: File is not a zip file
When I look at data.zip in Windows, it appears to be a valid zip file.
I am able to uncompress it in Windows XP, and can also uncompress it
with 7-Zip. It looks like zipfile is not able to read a table of
contents in the zip file. That's not a concept I'm familiar with.
No, ZipFile can read table of contents:
Help on method printdir in module zipfile:
printdir(self) unbound zipfile.ZipFile method
Print a table of contents for the zip file.
In my experience, zip files originating from Windows sometimes have
garbage at the end of the file. WinZip just ignores the garbage, but
other tools sometimes don't -- if I recall correctly, Linux unzip
successfully unzips the file but then complains that the file was
corrupt. It's possible that you're running into a similar problem.
data.zip is created in this script...
decoded = base64.b64decode(datum)
f = open('data.zip', 'wb')
f.write(decoded)
f.close()
file = zipfile.ZipFile('data.zip', r)
datum is a base64 encoded zip file. Again, I am able to open data.zip
as if it's a valid zip file. Maybe there is something wrong with the
approach I've taken to writing the data to data.zip? I'm not sure if it
matters, but the zipped data is Unicode.
The full signature of ZipFile is:
ZipFile(file, mode=r, compression=ZIP_STORED, allowZip64=True)
Try passing compression=zipfile.ZIP_DEFLATED and/or allowZip64=False and
see if that makes any difference.
compression is irrelevant when reading. The compression method used
is stored on a per-file basis, not on a per-archive basis, and it
hasn't got anywhere near per-file details when that exception is
raised. allowZip64 has not been used either.
The zip format does support alternative compression methods, it's
possible that this particular file uses a different sort of compression
which Python doesn't deal with.
What would cause a zip file to not have a table of contents?
What makes you think it doesn't have one?
--
Steven
--
http://mail.python.org/mailman/listinfo/python-list
Re: drive a desktop app from python?
On Jan 8, 9:06 pm, Tim Arnold tim.arn...@sas.com wrote: Is there any lib or recipe(s) for doing something like this via python? Look into the PyWin32 extension module. It gives access to Windows internals including the COM interface. You'll need to do some research into how to automate the GUI you're using from other sources (there are often VBA examples on the web that can be modified). http://pywin32.sourceforge.net/ I've successfully used this in the past for automating MS Excel. -- http://mail.python.org/mailman/listinfo/python-list
Re: Implementing file reading in C/Python
On Fri, 09 Jan 2009 19:33:53 +1000, James Mills wrote: On Fri, Jan 9, 2009 at 7:15 PM, Marc 'BlackJack' Rintsch bj_...@gmx.net wrote: Why parentheses around ``print``\s argument? In Python 3 ``print`` is a statement and not a function. Not true as of 2.6+ and 3.0+ print is now a function. Please read again what I wrote. Ciao, Marc 'BlackJack' Rintsch -- http://mail.python.org/mailman/listinfo/python-list
Re: Implementing file reading in C/Python
On Fri, Jan 9, 2009 at 7:41 PM, Marc 'BlackJack' Rintsch bj_...@gmx.net wrote: Please read again what I wrote. Lol I thought 3 was a smiley! :) Sorry! cheers James -- http://mail.python.org/mailman/listinfo/python-list
Re: Implementing file reading in C/Python
On Fri, 09 Jan 2009 04:04:41 +0100, Johannes Bauer wrote:
datamap = { }
for i in range(len(data)):
datamap[ord(data[i])] = datamap.get(data[i], 0) + 1
Here is an error by the way: You call `ord()` just on the left side of
the ``=``, so all keys in the dictionary are mapped to ones after the
loop which gives a pretty boring PGM. :-)
Ciao,
Marc 'BlackJack' Rintsch
--
http://mail.python.org/mailman/listinfo/python-list
Re: why cannot assign to function call
On Thu, 08 Jan 2009 18:33:50 +, Mark Wooding wrote: [Steven's message hasn't reached my server, so I'll reply to it here. Sorry if this is confusing.] Aaron Brady castiro...@gmail.com wrote: On Jan 8, 1:45 am, Steven D'Aprano ste...@remove.this.cybersource.com.au wrote: On Wed, 07 Jan 2009 10:17:55 +, Mark Wooding wrote: The `they're just objects' model is very simple, but gets tied up in knots explaining things. The `it's all references' model is only a little more complicated, but explains everything. But it *over* explains, because it implies things that everybody knows about references in other languages that aren't true for Python. I addressed this elsewhere. Summary: `pass-by-reference' is a different thing to `all you manipulate are references': You know, I've written a fair bit of Python code over the years, and I've never manipulated a reference *once*. Ints, strings, floats, lists, tuples... but references? Never. I'm pretty sure that no other pure-Python coder has manipulated references either. They've manipulated objects. Whatever the VM does under the hood is another story. If you insist on talking about implementations, then at least get it right: in Python, like every other programming language, all you do is flip bits. It's *all* bit flipping. That's why we should try to keep the different layers of explanation separate, without conflating them. Python programmers don't actually flip bits, and neither do they manipulate references. Python programmers don't have access to bits, or references. What they have access to is objects. (Of course, there are ways to get under the hood if you really want to.) Python does pass-by-value, but the things it passes -- by value -- are references. If you're going to misuse pass-by-value to describe what Python does, *everything* is pass-by-value where the value is foo, for some foo. You can't have anything but pass-by-value with current computer technology, because computers don't actually move arguments, they only copy bytes. So pass-by-value becomes a meaningless term, because it describes every computer language imaginable, including hypothetical ones using calling conventions not yet invented, and therefore explains nothing. (The `pass-by-*' notions are confusingly named anyway. Pass-by-name doesn't actually involve names at all.) You might find them confusing, but I don't. What I find confusing is that people insist on misusing terminology invented for describing one type of behaviour in order to use it for a completely different type of behaviour just because of certain similarities under the hood. Of course it's not literally true that everybody knows that you can use references to implement a swap(x, y) procedure. But people coming from a C or Pascal background tend to assume that everything is like C/Pascal, and there are a lot of them. If C was a rare, unfamiliar language, my opposition to using the term reference would be a lot milder. Maybe in another five years? I agree with the comment about Pascal, but C is actually pretty similar to Python here. C only does pass-by-value. Except for arrays. If you want a function to modify your variable, you have to pass a pointer value which points to it. Yes, because the variable is copied before the function sees it. So if you pass a struct, and modify one of the struct's fields, the caller doesn't see the change. Now try that with Python, and you'll see completely different behaviour. (You'll have to use something *like* a struct, because Python doesn't have them. Try an object with attributes.) In other words... C is call-by-value, and (according to you) Python is call-by-value, but they behaviour differently. Python has no pointer values, so you need a different hack. The hack usually involves lists. (Though it's easier in the main to return compound data objects like tuples. I don't suppose that a proposal for true multiple return values would go down well here. No, didn't think so...) Out of curiosity, what makes Python returning tuples less true than true multiple return values, and what can you do with TMRVs that you can't do with tuples? Okay, the abstraction has leaked again... are the paperweights references to the objects, or the names we've bound objects to? I'm confused... They're the references to the objects. You don't bind names to objects. Amazing. It sure feels like it to me. x = 23 There's a name, and an object, and I've bound the name to the object so I can refer to the object 23 by the name x. You bind names slots in which you store references. I'm pretty sure I don't. I'd have noticed. You may have missed my last question: How do we deal with anonymous objects in your model? What I am pretty sure of is that references are going to have to enter the picture at some point, because other models get too complicated. Well, I dare
Re: BadZipfile file is not a zip file
On Fri, 09 Jan 2009 00:46:27 -0800, Carl Banks wrote: On Jan 9, 2:16 am, Steven D'Aprano st...@remove-this- cybersource.com.au wrote: On Thu, 08 Jan 2009 16:47:39 -0800, webcomm wrote: The error... ... BadZipfile: File is not a zip file When I look at data.zip in Windows, it appears to be a valid zip file. I am able to uncompress it in Windows XP, and can also uncompress it with 7-Zip. It looks like zipfile is not able to read a table of contents in the zip file. That's not a concept I'm familiar with. No, ZipFile can read table of contents: Help on method printdir in module zipfile: printdir(self) unbound zipfile.ZipFile method Print a table of contents for the zip file. In my experience, zip files originating from Windows sometimes have garbage at the end of the file. WinZip just ignores the garbage, but other tools sometimes don't -- if I recall correctly, Linux unzip successfully unzips the file but then complains that the file was corrupt. It's possible that you're running into a similar problem. The zipfile format is kind of brain dead, you can't tell where the end of the file is supposed to be by looking at the header. If the end of file hasn't yet been reached there could be more data. To make matters worse, somehow zip files came to have text comments simply appended to the end of them. (Probably this was for the benefit of people who would cat them to the terminal.) Anyway, if you see something that doesn't adhere to the zipfile format, you don't have any foolproof way to know if it's because the file is corrupted or if it's just an appended comment. Yes, this has lead to a nice little attack vector, using hostile Java classes inside JAR files (a variant of ZIP). http://www.infoworld.com/article/08/08/01/ A_photo_that_can_steal_your_online_credentials_1.html or http://snipurl.com/9oh0e -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Fatal Python error: ceval: tstate mix-up
After upgrading my system, a program started to throw this error, and make a core dump: Fatal Python error: ceval: tstate mix-up Kernel log says: Jan 9 05:06:49 shopzeus kernel: pid 89184 (python), uid 1024: exited on signal 6 (core dumped) I found out that this can happen only when executing Python code without holding the GIL. My program is written entriely in Python, but uses some third part libraries: py25-json py25-psycopg2 Here is Python version: Python 2.5.2 (r252:60911, Nov 17 2008, 22:19:20) [GCC 4.2.1 20070719 [FreeBSD]] on freebsd7 (OS is FreeBSD 7.0 amd64 stable on dual quad core xeon 5420, it that matters...) I have the code dump, but I do not know how to debug that. What should I do? Thanks, Laszlo -- http://mail.python.org/mailman/listinfo/python-list
Re: Implementing file reading in C/Python
On Fri, 09 Jan 2009 19:33:53 +1000, James Mills wrote: On Fri, Jan 9, 2009 at 7:15 PM, Marc 'BlackJack' Rintsch bj_...@gmx.net wrote: print(Filesize : %d % (filesize)) print(Image size : %dx%d % (width, height)) print(Bytes per Pixel: %d % (blocksize)) Why parentheses around ``print``\s argument? In Python 3 ``print`` is a statement and not a function. Not true as of 2.6+ and 3.0+ print is now a function. Not so. print is still a statement in 2.6. $ python2.6 Python 2.6.1 (r261:67515, Dec 24 2008, 00:33:13) [GCC 4.1.2 20070502 (Red Hat 4.1.2-12)] on linux2 Type help, copyright, credits or license for more information. print 23 23 -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Implementing file reading in C/Python
On Fri, 09 Jan 2009 09:15:20 +, Marc 'BlackJack' Rintsch wrote:
picture = { }
havepixels = 0
while True:
data = f.read(blocksize)
if len(data) = 0: break
if data:
break
is enough.
You've reversed the sense of the test. The OP exits the loop when data is
empty, you exit the loop when it *isn't* empty.
--
Steven
--
http://mail.python.org/mailman/listinfo/python-list
Re: Encrypted Logging in python
On Fri, 09 Jan 2009 00:21:09 -0800, koranthala wrote: I was wondering if there is a mechanism to encrypt logging automatically in python. The issue is as follows: (a) An application (after py2exe) will go as executable and there is no need for the user to know that it is written in python. If an exception occurs and it is logged, then the user can understand it is written in python. (b) A security threat. If an exception occurs, the code is seen by the user - and possibly be misused. Security by obscurity is not security. If your application isn't secure against people who know what language is written in, then it isn't secure. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Implementing file reading in C/Python
On Fri, 09 Jan 2009 04:04:41 +0100, Johannes Bauer wrote:
As this was horribly slow (20 Minutes for a 2GB file) I coded the whole
thing in C also:
Yours took ~37 minutes for 2 GiB here. This just ~15 minutes:
#!/usr/bin/env python
from __future__ import division, with_statement
import os
import sys
from collections import defaultdict
from functools import partial
from itertools import imap
def iter_max_values(blocks, block_count):
for i, block in enumerate(blocks):
histogram = defaultdict(int)
for byte in block:
histogram[byte] += 1
yield max((count, byte)
for value, count in histogram.iteritems())[1]
if i % 1024 == 0:
print 'Progresss: %.1f%%' % (100 * i / block_count)
def write_pgm(filename, width, height, pixel_values):
with open(filename, 'w') as pgm_file:
pgm_file.write('P2\n'
'# CREATOR: Crappyass Python Script\n'
'%d %d\n'
'255\n' % (width, height))
pgm_file.writelines('%d\n' % value for value in pixel_values)
def main():
filename = sys.argv[1]
filesize = os.path.getsize(filename)
width = 1024
height = 1024
pixels = width * height
blocksize = filesize // width // height
print 'Filesize : %d' % filesize
print 'Image size : %dx%d' % (width, height)
print 'Bytes per Pixel: %d' % blocksize
with open(filename, 'rb') as data_file:
blocks = iter(partial(data_file.read, blocksize), '')
pixel_values = imap(ord, iter_max_values(blocks, pixels))
write_pgm(filename + '.pgm', width, height, pixel_values)
if __name__ == '__main__':
main()
Ciao,
Marc 'BlackJack' Rintsch
--
http://mail.python.org/mailman/listinfo/python-list
Re: Best practice in organize classes into modules
Steven Woody a écrit : On Fri, Jan 9, 2009 at 4:54 PM, Bruno Desthuilliers bruno.42.desthuilli...@websiteburo.invalid wrote: Steven Woody a écrit : On Fri, Jan 9, 2009 at 1:02 PM, James Mills prolo...@shortcircuit.net.au wrote: On Fri, Jan 9, 2009 at 2:57 PM, Steven Woody narkewo...@gmail.com wrote: In C++/Java, people usually put one class into one file. What's the suggestion on this topic in Python? I so much interesting this especially when exception classes also involved. Normally i group related functionality into the one module. Will that lead to too large source file size? When the case happens, then you can safely refactor the module into a package with submodules, and use the package's __init__.py to make it a facade for the submodules so the refactoring is transparent for client code. really a smart idea. Mostly a common Python idiom. Did you mean putting some 'import statement in __init__.py and use the old module name as the new package name? Yes, you guessed. -- http://mail.python.org/mailman/listinfo/python-list
Re: Implementing file reading in C/Python
Marc 'BlackJack' Rintsch wrote: On Fri, 09 Jan 2009 04:04:41 +0100, Johannes Bauer wrote: [...] print(Filesize : %d % (filesize)) print(Image size : %dx%d % (width, height)) print(Bytes per Pixel: %d % (blocksize)) Why parentheses around ``print``\s argument? In Python 3 ``print`` is a statement and not a function. Portability? regards Steve -- Steve Holden+1 571 484 6266 +1 800 494 3119 Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: BadZipfile file is not a zip file
On Jan 9, 7:46 pm, Carl Banks pavlovevide...@gmail.com wrote: On Jan 9, 2:16 am, Steven D'Aprano st...@remove-this- cybersource.com.au wrote: On Thu, 08 Jan 2009 16:47:39 -0800, webcomm wrote: The error... ... BadZipfile: File is not a zip file When I look at data.zip in Windows, it appears to be a valid zip file. I am able to uncompress it in Windows XP, and can also uncompress it with 7-Zip. It looks like zipfile is not able to read a table of contents in the zip file. That's not a concept I'm familiar with. No, ZipFile can read table of contents: Help on method printdir in module zipfile: printdir(self) unbound zipfile.ZipFile method Print a table of contents for the zip file. In my experience, zip files originating from Windows sometimes have garbage at the end of the file. WinZip just ignores the garbage, but other tools sometimes don't -- if I recall correctly, Linux unzip successfully unzips the file but then complains that the file was corrupt. It's possible that you're running into a similar problem. The zipfile format is kind of brain dead, you can't tell where the end of the file is supposed to be by looking at the header. If the end of file hasn't yet been reached there could be more data. To make matters worse, somehow zip files came to have text comments simply appended to the end of them. (Probably this was for the benefit of people who would cat them to the terminal.) Anyway, if you see something that doesn't adhere to the zipfile format, you don't have any foolproof way to know if it's because the file is corrupted or if it's just an appended comment. Most zipfile readers use a heuristic to distinguish. Python's zipfile module just assumes it's corrupted. The following post from a while back gives a solution that tries to snip the comment off so that zipfile module can handle it. It might help you out. http://groups.google.com/group/comp.lang.python/msg/c2008e48368c6543 And here's a little gadget that might help the diagnostic effort; it shows the archive size and the position of all the magic PKnn markers. In a normal uncommented archive, EndArchive_pos + 22 == archive_size. 8--- # usage: python zip_susser.py name_of_archive.zip import sys grimoire = [ (FileHeader, PK\003\004), # magic number for file header (CentralDir, PK\001\002), # magic number for central directory (EndArchive, PK\005\006), # magic number for end of archive record (EndArchive64,PK\x06\x06), # magic token for Zip64 header (EndArchive64Locator, PK\x06\x07), # magic token for locator header ] f = open(sys.argv[1], 'rb') buff = f.read() f.close() blen = len(buff) print archive size is, blen for magic_name, magic in grimoire: pos = 0 while pos blen: pos = buff.find(magic, pos) if pos 0: break print %s at %d % (magic_name, pos) pos += 4 8--- HTH, John -- http://mail.python.org/mailman/listinfo/python-list
Re: Implementing file reading in C/Python
Steven D'Aprano wrote: On Fri, 09 Jan 2009 19:33:53 +1000, James Mills wrote: On Fri, Jan 9, 2009 at 7:15 PM, Marc 'BlackJack' Rintsch bj_...@gmx.net wrote: print(Filesize : %d % (filesize)) print(Image size : %dx%d % (width, height)) print(Bytes per Pixel: %d % (blocksize)) Why parentheses around ``print``\s argument? In Python 3 ``print`` is a statement and not a function. Not true as of 2.6+ and 3.0+ print is now a function. Not so. print is still a statement in 2.6. $ python2.6 Python 2.6.1 (r261:67515, Dec 24 2008, 00:33:13) [GCC 4.1.2 20070502 (Red Hat 4.1.2-12)] on linux2 Type help, copyright, credits or license for more information. print 23 23 C:\Users\sholden\python26\python Python 2.6 (r26:66721, Oct 2 2008, 11:35:03) [MSC v.1500 32 bit (Intel)] on win32 Type help, copyright, credits or license for more information. print built-in function print OK, I confess I missed out from __future__ import print_function regards Steve -- Steve Holden+1 571 484 6266 +1 800 494 3119 Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
Line completion with custom commands
Hi, my Python program can be launched with a range of different options (or subcommands) like: $ myProgram doSomething $ myProgram doSomethingElse $ myProgram nowDoSomethingDifferent I want it to use auto-completion with so that if i type myProgram d it returns myProgram doSomething and if i type myProgram n it renders myProgram nowDoSomethingDifferent. This is similar to the average use of the module rlcompleter, but it does not pick possible completion options from the filesystem (or from history) but from a custom set of strings (that correspond to the available options for my program) Any idea on how to implement this? I'm aware of the variable PYTHONSTARTUP (that should point to a file I don't know how to write). As a working example, django-admin (from the django package) has the same exact feature i'm looking for -- http://mail.python.org/mailman/listinfo/python-list
Re: [Python-Dev] compiling python2.5 on linux under wine
On Thu, Jan 8, 2009 at 9:07 PM, Martin v. Löwis mar...@v.loewis.de wrote: i'd just ... much rather be completely independent of proprietary software when it comes to building free software. I guess my question is then: why do you want to use Windows in the first place? ha ha :) the same question was asked when i started the nt domains reverse-engineering for samba, in 1996. the answer is: i don't. but there are a lot of users and developers who feel that they don't have a choice. or haven't been given one. so if it's possible for me, as one of the under 1% of computer users i.e. linux to compile stuff that will work on the over 95% of computers used by everyone else i.e. windows _and_ i get to stick to free software principles, that's gotta be good. take pywebkit-gtk as an example. the first-level (and some of the second-level) dependencies for pywebkit-gtk are roughly as follows: * libstdc++ * cairo, pango, gdk, fontconfig, gtk * libxml2 (which is dodgy) * libxslt1 (which is so dodgy and dependent on incompatible versions of libxml2 it can't be compiled on win32) * libicu38 * libcurl * libssl * webkit * python2.5 * python-gobect * python-gtk that's a *big* ing list that comes in at a whopping 40mb of _binaries_. webkit itself comes in at 10mb alone. libicu38 fails _miserably_ to cross-compile with mingw32. i was damn lucky to have beaten it into submission: it took two days and i couldn't run any of the tests, but actually managed to get at least some .libs, .dlls and .a's out of the mess. libxslt1 and libxml2 have compile errors in mutually incompatible versions on win32, plus, unfortunately, the versions that _do_ compile correctly (really old versions like libxslt-1.12 + libxml2-18 or something) are not the ones that can be used on webkit! i had to get the source code for gcc (4.4) because when linking webkit against the MSVC-compiled libicu38 gcc actually segfaulted (!). and that was tracked down to exception handling across process / thread boundaries in libstdc++-6 which had only literally been fixed/patched a few days before i started the monster-compile-process. i tried hunting down python-gobject and python-gtk for win32, but there is a dependency needed before you get to that: python25.lib. as i mentioned previously i tried hunting down a .lib for python25 but of course that would be useless unless i also have a libtool-compiled .a so there wasn't any point. so, all the hard work that i did cross-compiling up webkit for win32 was completely wasted because python itself could not be compiled on linux for a win32 platform. hence my interest in making sure that it can be. _then_ i can go back and revisit the monster compile process and finally come up with the goods, on win32, on the gobject-based DOM-model manipulation stuff i've added to pywebkit-gtk. i've got linux covered, i've got macosx covered. win32 is the last one. l. -- http://mail.python.org/mailman/listinfo/python-list
Re: Implementing file reading in C/Python
Johannes Bauer wrote: Which takes about 40 seconds. I want the niceness of Python but a little more speed than I'm getting (I'd settle for factor 2 or 3 slower, but factor 30 is just too much). This probably doesn't contribute much, but have you tried using Python profiler? You might have *something* wrong that eats up a lot of time in the code. The factor of 30 indeed does not seem right -- I have done somewhat similar stuff (calculating Levenshtein distance [edit distance] on words read from very large files), coded the same algorithm in pure Python and C++ (using linked lists in C++) and Python version was 2.5 times slower. Regards, mk -- http://mail.python.org/mailman/listinfo/python-list
Re: Line completion with custom commands
gu wrote: Hi, my Python program can be launched with a range of different options (or subcommands) like: $ myProgram doSomething $ myProgram doSomethingElse $ myProgram nowDoSomethingDifferent I want it to use auto-completion with so that if i type myProgram d it returns myProgram doSomething and if i type myProgram n it renders myProgram nowDoSomethingDifferent. This is similar to the average use of the module rlcompleter, but it does not pick possible completion options from the filesystem (or from history) but from a custom set of strings (that correspond to the available options for my program) Any idea on how to implement this? I'm aware of the variable PYTHONSTARTUP (that should point to a file I don't know how to write). As a working example, django-admin (from the django package) has the same exact feature i'm looking for The issue here is that Python doesn't get control until afer you've hit RETURN on the command line. so nothing you can do in your program or interpreter setup will have any effect on how the command shell behaves. regards Steve -- Steve Holden+1 571 484 6266 +1 800 494 3119 Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: figuring week of the day....
Tim Chase wrote: tekion wrote: Is there a module where you could figure week of the day, like where it starts and end. I need to do this for a whole year. Thanks. the monthcalendar() call returns the whole month's calendar which may be more what you want for the big-picture. And if you want a whole year's worth, you can get pretty close with: import itertools as i import calendar as c for month in range(1,13): for week in c.monthcalendar(2009, month): print repr(w) You don't detail how you want the month-boundaries to behave, so this gives calendar's default behavior of filling in zeros on month-boundaries, so November through the 1st week in Dec 2009 comes back as ... [0, 0, 0, 0, 0, 0, 1], [2, 3, 4, 5, 6, 7, 8], [9, 10, 11, 12, 13, 14, 15], [16, 17, 18, 19, 20, 21, 22], [23, 24, 25, 26, 27, 28, 29], [30, 0, 0, 0, 0, 0, 0], [0, 1, 2, 3, 4, 5, 6], ... rather than ... [26, 27, 28, 29, 30, 31, 1], [2, 3, 4, 5, 6, 7, 8], [9, 10, 11, 12, 13, 14, 15], [16, 17, 18, 19, 20, 21, 22], [23, 24, 25, 26, 27, 28, 29], [30, 1, 2, 3, 4, 5, 6], ... -tkc -- http://mail.python.org/mailman/listinfo/python-list
Re: Line completion with custom commands
Steve Holden wrote: gu wrote: Hi, my Python program can be launched with a range of different options (or subcommands) like: $ myProgram doSomething $ myProgram doSomethingElse $ myProgram nowDoSomethingDifferent I want it to use auto-completion with so that if i type myProgram d it returns myProgram doSomething and if i type myProgram n it renders myProgram nowDoSomethingDifferent. This is similar to the average use of the module rlcompleter, but it does not pick possible completion options from the filesystem (or from history) but from a custom set of strings (that correspond to the available options for my program) Any idea on how to implement this? I'm aware of the variable PYTHONSTARTUP (that should point to a file I don't know how to write). As a working example, django-admin (from the django package) has the same exact feature i'm looking for The issue here is that Python doesn't get control until afer you've hit RETURN on the command line. so nothing you can do in your program or interpreter setup will have any effect on how the command shell behaves. regards Steve I see, but how does django-admin work, then? -- http://mail.python.org/mailman/listinfo/python-list
Re: Line completion with custom commands
gu wrote: I see, but how does django-admin work, then? from bash: complete -W doSomething doSomethingElse doSomethingDifferent myProgram -- http://mail.python.org/mailman/listinfo/python-list
Re: why cannot assign to function call
On Jan 9, 4:01 am, Steven D'Aprano st...@remove-this- cybersource.com.au wrote: On Thu, 08 Jan 2009 18:33:50 +, Mark Wooding wrote: [Steven's message hasn't reached my server, so I'll reply to it here. Sorry if this is confusing.] Aaron Brady castiro...@gmail.com wrote: On Jan 8, 1:45 am, Steven D'Aprano ste...@remove.this.cybersource.com.au wrote: On Wed, 07 Jan 2009 10:17:55 +, Mark Wooding wrote: The `they're just objects' model is very simple, but gets tied up in knots explaining things. The `it's all references' model is only a little more complicated, but explains everything. But it *over* explains, because it implies things that everybody knows about references in other languages that aren't true for Python. I addressed this elsewhere. Summary: `pass-by-reference' is a different thing to `all you manipulate are references': You know, I've written a fair bit of Python code over the years, and I've never manipulated a reference *once*. Ints, strings, floats, lists, tuples... but references? Never. snip That's why we should try to keep the different layers of explanation separate, without conflating them. Python programmers don't actually flip bits, and neither do they manipulate references. Python programmers don't have access to bits, or references. What they have access to is objects. snip How do we deal with anonymous objects in your model? What I am pretty sure of is that references are going to have to enter the picture at some point, because other models get too complicated. Well, I dare say that at *some* point all models are insufficient. The map is not the territory, and there's always something that gets left out. But I think your model with strings is more complicated: robots, sticky Blu-Tack, string that you can't touch or see, and so forth. Compared to that, TARDIS technology enabling objects to be in two places at once is remarkably straightforward. Despite it being physically unrealistic, it's logically simple. -- Steven Possible compromise. You can think of functions as mutation-only. You pass the object, and it gets a new (additional) name. The old name doesn't go in. /compromise Regardless, IMO, references don't add any explanatory power; they just make you feel cocky that you know what they are. M: If 'fun()' returned a reference, you would be able to assign to it. m: You can't assign to it. C: It doesn't return a reference. -- Why can't I assign to a function call? -- Python variables are references only. -- Ok, why can't I assign to a function call? -- [Explanation Steven is trying to give.] In other words, Mark and Joe, cut to the chase. You're shirking. -- http://mail.python.org/mailman/listinfo/python-list
Re: Line completion with custom commands
gu wrote: Steve Holden wrote: gu wrote: Hi, my Python program can be launched with a range of different options (or subcommands) like: $ myProgram doSomething $ myProgram doSomethingElse $ myProgram nowDoSomethingDifferent I want it to use auto-completion with so that if i type myProgram d it returns myProgram doSomething and if i type myProgram n it renders myProgram nowDoSomethingDifferent. This is similar to the average use of the module rlcompleter, but it does not pick possible completion options from the filesystem (or from history) but from a custom set of strings (that correspond to the available options for my program) Any idea on how to implement this? I'm aware of the variable PYTHONSTARTUP (that should point to a file I don't know how to write). As a working example, django-admin (from the django package) has the same exact feature i'm looking for The issue here is that Python doesn't get control until afer you've hit RETURN on the command line. so nothing you can do in your program or interpreter setup will have any effect on how the command shell behaves. regards Steve I see, but how does django-admin work, then? Probably the issue you has was not knowing the name of the feature. When I asked Google to tell me about django-admin command completion it said: http://code.djangoproject.com/ticket/1240 as the first hit. As you will see, this is done by configuring the shell to know about the specific commands it has to deal with. Enjoy! regards Steve -- Steve Holden+1 571 484 6266 +1 800 494 3119 Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Line completion with custom commands
Marco Mariani wrote: gu wrote: I see, but how does django-admin work, then? from bash: complete -W doSomething doSomethingElse doSomethingDifferent myProgram This worked like a charm, thank you so much. Is this available for bash only or any shell? -- http://mail.python.org/mailman/listinfo/python-list
Re: [Help] The pywinauto Can't select the MDI's menu using the MenuItems() which return [].
2008/12/22 Simon Brunning si...@brunningonline.net 2008/12/21 gagsl-...@yahoo.com.ar: The code below opens the Choose Font dialog on my Spanish Windows version: py from pywinauto.application import Application py app = Application.start(Notepad.exe) Notepad's menus are build with MFC. Word's menus are not. Trust me, give it up. For automating Word, COM (with Mark Hammond's excellent Python/COM bridge) is the only way to go. Yeah. But the GuiLib program also don't work. You can dowload sample from http://www.beyondata.com/ and use the pywinauto to test it. I want to know how to do the GuiLib's automation. -- Cheers, Simon B. si...@brunningonline.net -- http://mail.python.org/mailman/listinfo/python-list -- OpenBookProject-开放图书计划邮件列表 详情: http://groups.google.com/group/OpenBookProject 维基: http://wiki.woodpecker.org.cn/ -- http://mail.python.org/mailman/listinfo/python-list
Re: drive a desktop app from python?
Is there any lib or recipe(s) for doing something like this via python? I've used pywinauto to do something similar, and found it good. http://pywinauto.openqa.org/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Unexpected scientific notation
On Jan 8, 1:00 am, Paul McNett p...@ulmcnett.com wrote:
It displays '3E+1' instead of '30.0'.
As I can't reproduce I'm looking for an idea brainstorm of what could be
causing
this. What would be choosing to display such a normal number in scientific
notation?
Ideas?
[I thought I replied to this earlier, but the post isn't showing up.
So here it is again.]
I suspect it's your use of the Decimal normalize() method that's
causing
this. Trailing zeros on Decimal instances are significant, so
Decimal('30.0'), Decimal('30') and Decimal('3E+1') are considered
distinct (though they all have the same value). The normalize method
strips all trailing zeros, turning Decimal('30.0') into Decimal('3E
+1').
One way to get around this is to add 0 after normalizing: this will
make sure that scientific notation is used only for very large
or small numbers, as usual.
Python 2.7a0 (trunk:68298:68318, Jan 6 2009, 10:39:14)
[GCC 4.0.1 (Apple Inc. build 5490)] on darwin
Type help, copyright, credits or license for more information.
from decimal import Decimal
0 + Decimal('3E1')
Decimal('30')
Decimal('0.0') + Decimal('3E1')
Decimal('30.0')
Adding 0 also has the side-effect of turning a negative zero
into a positive zero, but I suspect that this isn't going to
worry you much. :)
You might also want to look at the Decimal.quantize method.
Mark
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Re: Fatal Python error: ceval: tstate mix-up
I could start gdb python python.core but don't know what it means. Unfortunately, there are no debugging symbols. %gdb /usr/local/bin/python python.core GNU gdb 6.1.1 [FreeBSD] Copyright 2004 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type show copying to see the conditions. There is absolutely no warranty for GDB. Type show warranty for details. This GDB was configured as amd64-marcel-freebsd...(no debugging symbols found)... Core was generated by `python'. Program terminated with signal 6, Aborted. Reading symbols from /lib/libutil.so.7...(no debugging symbols found)...done. Loaded symbols for /lib/libutil.so.7 Reading symbols from /lib/libm.so.5...(no debugging symbols found)...done. Loaded symbols for /lib/libm.so.5 Reading symbols from /lib/libthr.so.3...(no debugging symbols found)...done. Loaded symbols for /lib/libthr.so.3 Reading symbols from /lib/libc.so.7...(no debugging symbols found)...done. Loaded symbols for /lib/libc.so.7 Reading symbols from /usr/local/lib/python2.5/lib-dynload/time.so...(no debugging symbols found)...done. Loaded symbols for /usr/local/lib/python2.5/lib-dynload/time.so Reading symbols from /usr/local/lib/python2.5/lib-dynload/collections.so...(no debugging symbols found)...done. Loaded symbols for /usr/local/lib/python2.5/lib-dynload/collections.so Reading symbols from /usr/local/lib/python2.5/lib-dynload/datetime.so...(no debugging symbols found)...done. Loaded symbols for /usr/local/lib/python2.5/lib-dynload/datetime.so Reading symbols from /usr/local/lib/python2.5/lib-dynload/cStringIO.so...(no debugging symbols found)...done. Loaded symbols for /usr/local/lib/python2.5/lib-dynload/cStringIO.so Reading symbols from /usr/local/lib/python2.5/lib-dynload/strop.so...(no debugging symbols found)...done. Loaded symbols for /usr/local/lib/python2.5/lib-dynload/strop.so Reading symbols from /usr/local/lib/python2.5/lib-dynload/operator.so...(no debugging symbols found)...done. Loaded symbols for /usr/local/lib/python2.5/lib-dynload/operator.so Reading symbols from /usr/local/lib/python2.5/lib-dynload/_struct.so...(no debugging symbols found)...done. Loaded symbols for /usr/local/lib/python2.5/lib-dynload/_struct.so Reading symbols from /usr/local/lib/python2.5/lib-dynload/binascii.so...(no debugging symbols found)...done. Loaded symbols for /usr/local/lib/python2.5/lib-dynload/binascii.so Reading symbols from /usr/local/lib/python2.5/site-packages/sgmlop.so...(no debugging symbols found)...done. Loaded symbols for /usr/local/lib/python2.5/site-packages/sgmlop.so Reading symbols from /usr/local/lib/python2.5/lib-dynload/pyexpat.so...(no debugging symbols found)...done. Loaded symbols for /usr/local/lib/python2.5/lib-dynload/pyexpat.so Reading symbols from /usr/local/lib/python2.5/lib-dynload/_socket.so...(no debugging symbols found)...done. Loaded symbols for /usr/local/lib/python2.5/lib-dynload/_socket.so Reading symbols from /usr/local/lib/python2.5/lib-dynload/_ssl.so...(no debugging symbols found)...done. Loaded symbols for /usr/local/lib/python2.5/lib-dynload/_ssl.so Reading symbols from /usr/lib/libssl.so.5...(no debugging symbols found)...done. Loaded symbols for /usr/lib/libssl.so.5 Reading symbols from /lib/libcrypto.so.5...(no debugging symbols found)...done. Loaded symbols for /lib/libcrypto.so.5 Reading symbols from /usr/local/lib/python2.5/lib-dynload/math.so...(no debugging symbols found)...done. Loaded symbols for /usr/local/lib/python2.5/lib-dynload/math.so Reading symbols from /usr/local/lib/python2.5/lib-dynload/_random.so...(no debugging symbols found)...done. Loaded symbols for /usr/local/lib/python2.5/lib-dynload/_random.so Reading symbols from /usr/local/lib/python2.5/lib-dynload/fcntl.so...(no debugging symbols found)...done. Loaded symbols for /usr/local/lib/python2.5/lib-dynload/fcntl.so Reading symbols from /usr/local/lib/python2.5/lib-dynload/select.so...(no debugging symbols found)...done. Loaded symbols for /usr/local/lib/python2.5/lib-dynload/select.so Reading symbols from /usr/local/lib/python2.5/site-packages/OpenSSL/rand.so...(no debugging symbols found)...done. Loaded symbols for /usr/local/lib/python2.5/site-packages/OpenSSL/rand.so Reading symbols from /usr/local/lib/python2.5/site-packages/OpenSSL/crypto.so...(no debugging symbols found)...done. Loaded symbols for /usr/local/lib/python2.5/site-packages/OpenSSL/crypto.so Reading symbols from /usr/local/lib/python2.5/site-packages/OpenSSL/SSL.so...(no debugging symbols found)...done. Loaded symbols for /usr/local/lib/python2.5/site-packages/OpenSSL/SSL.so Reading symbols from /usr/local/lib/python2.5/lib-dynload/cPickle.so...(no debugging symbols found)...done. Loaded symbols for /usr/local/lib/python2.5/lib-dynload/cPickle.so Reading symbols from /usr/local/lib/python2.5/lib-dynload/_weakref.so...(no debugging symbols found)...done. Loaded symbols
pySerial - accessing GSM module failed
Hello all,
I'm newbie in the serial buissness and I beed some Help. I'm a student at my
last year and I got final assaignment.
My goal is to comunicate with SIM free, GSM Module through computer. I want
to simulate SIM card by receiving and transferring data from my code.
In order to understand how to comunicate with the GSM module I took an
existing module which gut RS232 connector and connected it to the computer.
I ran my python code:
class MySerial():
def __init__ (self,port,baundrate,)
self.s = serial.Serial(port,baundreate,)
def read(self,size=1):
txt = self.s.read(size)
def write(self,text=''):txt = self.s.write(text)
def main():
obj = MySerial('COM1')
obj.write('ATI')
sleep(1)
obj.read(10)
the code run and I send the comman 'ATI' which ask the GSM Module if
everything is OK.
the read line returs 'ATI'. echo to my write function.
Whenever I run this comman ('ATI') through hyperterminal I gut the result :
232 OK
Does any one got an Idea why my code isn't getting the same answer from the
GSM Module?
thanks
dave
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Re: Implementing file reading in C/Python
Marc 'BlackJack' Rintsch schrieb:
f = open(sys.argv[1], r)
Mode should be 'rb'.
Check.
filesize = os.stat(sys.argv[1])[6]
`os.path.getsize()` is a little bit more readable.
Check.
print(Filesize : %d % (filesize)) print(Image size : %dx%d
% (width, height)) print(Bytes per Pixel: %d % (blocksize))
Why parentheses around ``print``\s argument? In Python 3 ``print`` is
a statement and not a function.
I write all new code to work under Python3.0. Actually I develop on
Python 3.0 but the code is currently deployed onto 2.6.
picture = { }
havepixels = 0
while True:
data = f.read(blocksize)
if len(data) = 0: break
if data:
break
is enough.
datamap = { }
for i in range(len(data)):
datamap[ord(data[i])] = datamap.get(data[i], 0) + 1
Here you are creating a list full of integers to use them as index into
`data` (twice) instead of iterating directly over the elements in
`data`. And you are calling `ord()` for *every* byte in the file
although you just need it for one value in each block. If it's possible
to write the raw PGM format this conversion wouldn't be necessary at all.
OK, those two are just stupid, you're right. I changed it to:
datamap = { }
for i in data:
datamap[i] = datamap.get(i, 0) + 1
array = sorted([(b, a) for (a, b) in datamap.items()], reverse=True)
most = ord(array[0][1])
pic.write(%d\n % (most))
For the `datamap` a `collections.defaultdict()` might be faster.
Tried that, not much of a change.
maxchr = None
maxcnt = None
for (char, count) in datamap.items():
if (maxcnt is None) or (count maxcnt):
maxcnt = count
maxchr = char
Untested:
maxchr = max((i, c) for c, i in datamap.iteritems())[1]
This is nice, I use it - the sort thing was a workaround anyways.
most = maxchr
Why?
I don't really know anymore :-\
posx = havepixels % width
posy = havepixels / width
posx, posy = divmod(havepixels, width)
That's a nice one.
Why are you using a dictionary as 2d array? In the C code you simply
write the values sequentially, why can't you just use a flat list and
append here?
Yup, I changed the Python code to behave the same way the C code did -
however overall it's not much of an improvement: Takes about 15 minutes
to execute (still factor 23).
Thanks for all your pointers!
Kind regards,
Johannes
--
Meine Gegenklage gegen dich lautet dann auf bewusste Verlogenheit,
verlästerung von Gott, Bibel und mir und bewusster Blasphemie.
-- Prophet und Visionär Hans Joss aka HJP in de.sci.physik
48d8bf1d$0$7510$54022...@news.sunrise.ch
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Re: Implementing file reading in C/Python
James Mills schrieb: What does this little tool do anyway ? It's very interesting the images it creates out of files. What is this called ? It has no particular name. I was toying around with the Princeton Cold Boot Attack (http://citp.princeton.edu/memory/). In particular I was interested in how much memory is erased when I would (on my system) enable the slow POST (which counts through all RAM three times). I downloaded the provided utitilities, dumped my system memory via PXE boot onto another system after resetting it hard in the middle of a running Linux session. I did sync, though. Praise all journaling filesystems. As a 2GB file is not really of much use for telling where something is and where isn't, I thought of that picture coloring. In a 1024x1024 picture a pixel is 2048 bytes with 2GB of RAM, so exactly half a page. This is sufficiently high resolution to detect what's in there. I'm curious :) I haven't had much tiem to optimize it yet - I'll try to when I get home from work. Thanks for your effort, I appreciate it... hope my work leads to some meaningful results. Currently it looks (*cough* if there aren't bugs in my picture code) as if my PC would reset the whole RAM anyways, although I do not have any ECC. Strange. Kind regards, Johannes -- Meine Gegenklage gegen dich lautet dann auf bewusste Verlogenheit, verlästerung von Gott, Bibel und mir und bewusster Blasphemie. -- Prophet und Visionär Hans Joss aka HJP in de.sci.physik 48d8bf1d$0$7510$54022...@news.sunrise.ch -- http://mail.python.org/mailman/listinfo/python-list
Re: Implementing file reading in C/Python
Marc 'BlackJack' Rintsch schrieb: On Fri, 09 Jan 2009 04:04:41 +0100, Johannes Bauer wrote: As this was horribly slow (20 Minutes for a 2GB file) I coded the whole thing in C also: Yours took ~37 minutes for 2 GiB here. This just ~15 minutes: Ah, ok... when implementing your suggestions int he other post, I did not get such a drastic performance increase. I really will have a look at it and try to locate where I'm wasting the time. Thanks a lot, Kind regards, Johannes -- Meine Gegenklage gegen dich lautet dann auf bewusste Verlogenheit, verlästerung von Gott, Bibel und mir und bewusster Blasphemie. -- Prophet und Visionär Hans Joss aka HJP in de.sci.physik 48d8bf1d$0$7510$54022...@news.sunrise.ch -- http://mail.python.org/mailman/listinfo/python-list
Re: Implementing file reading in C/Python
mk schrieb: Johannes Bauer wrote: Which takes about 40 seconds. I want the niceness of Python but a little more speed than I'm getting (I'd settle for factor 2 or 3 slower, but factor 30 is just too much). This probably doesn't contribute much, but have you tried using Python profiler? You might have *something* wrong that eats up a lot of time in the code. No - and I've not known there was a profiler yet have found anything meaningful (there seems to be an profiling C interface, but that won't get me anywhere). Is that a seperate tool or something? Could you provide a link? The factor of 30 indeed does not seem right -- I have done somewhat similar stuff (calculating Levenshtein distance [edit distance] on words read from very large files), coded the same algorithm in pure Python and C++ (using linked lists in C++) and Python version was 2.5 times slower. Yup, that was about what I had expected (and what I could well live with, it's a tradeoff). Thanks, Kind regards, Johannes -- Meine Gegenklage gegen dich lautet dann auf bewusste Verlogenheit, verlästerung von Gott, Bibel und mir und bewusster Blasphemie. -- Prophet und Visionär Hans Joss aka HJP in de.sci.physik 48d8bf1d$0$7510$54022...@news.sunrise.ch -- http://mail.python.org/mailman/listinfo/python-list
Re: Force exception on attribute write access only one object
Hi Peter and others, your idea was good, but it does not work with Django ORM Models: Traceback (most recent call last): File /localhome/modw/django/core/handlers/base.py, line 87, in get_response response = callback(request, *callback_args, **callback_kwargs) File /localhome/modw/foo/views/filter.py, line 473, in add return edit(request, 'add') File /localhome/modw/foo/views/filter.py, line 493, in edit filter=form.save() File /localhome/modw/foo/views/filter.py, line 457, in save action=form.save() File /localhome/modw/django/forms/models.py, line 315, in save if self.instance.pk is None: File /localhome/modw/django/db/models/base.py, line 292, in _get_pk_val return getattr(self, meta.pk.attname) AttributeError: 'MyAction' object has no attribute 'filter_action_ptr_id' Peter Otten schrieb: Thomas Guettler wrote: for debugging I want to raise an exception if an attribute is changed on an object. Since it is only for debugging I don't want to change the integer attribute to a property. Why? This should raise an exception: myobj.foo=1 Background: Somewhere this value gets changed. But I don't now where. If you change your mind: class A(object): def __init__(self): self.foo = 42 a = A() b = A() class B(A): @property def foo(self): return self.__dict__[foo] b.__class__ = B a.foo = whatever print b.foo b.foo = whatever Peter -- Thomas Guettler, http://www.thomas-guettler.de/ E-Mail: guettli (*) thomas-guettler + de -- http://mail.python.org/mailman/listinfo/python-list
Re: Encrypted Logging in python
On Jan 9, 3:16 pm, Steven D'Aprano st...@remove-this- cybersource.com.au wrote: On Fri, 09 Jan 2009 00:21:09 -0800, koranthala wrote: I was wondering if there is a mechanism to encrypt logging automatically in python. The issue is as follows: (a) An application (after py2exe) will go as executable and there is no need for the user to know that it is written in python. If an exception occurs and it is logged, then the user can understand it is written in python. (b) A security threat. If an exception occurs, the code is seen by the user - and possibly be misused. Security by obscurity is not security. If your application isn't secure against people who know what language is written in, then it isn't secure. -- Steven I understand that completely. My point is that even though I can try to make the application completely secure - I can never be sure of that. Especially if your company is a very small one - and might not be able to have the best programmers around. So, another layer of security - even security through obscurity - can give that bit extra time in which the bugs in the system can be ironed out. Also, what I am asking is a generic option in logging - which can help the adoption of the logging framework in even closed source systems. It is not just about security - just that a closed source company might be much more comfortable in using the system if crypt is there. -- http://mail.python.org/mailman/listinfo/python-list
Re: Fatal Python error: ceval: tstate mix-up
Meanwhile I'm trying to turn off threads in that program one by one. I just got this new type of error: Fatal Python error: PyThreadState_Delete: invalid tstate -- http://mail.python.org/mailman/listinfo/python-list
win32gui
Hi, everyone I'm searching the win32gui lib to find a way to get the text under the user cursor. so far I managed to find only the controller ID which under the cursor this way cursorID = win32gui.WindowFromPoint(win32gui.GetCursorPos()) their is function called GetWindowText I tried to use but it doesn't work in most of the time someone know a way to do this? thank you! -- http://mail.python.org/mailman/listinfo/python-list
Re: win32gui
On Jan 9, 7:34 am, Gandalf goldn...@gmail.com wrote: Hi, everyone I'm searching the win32gui lib to find a way to get the text under the user cursor. so far I managed to find only the controller ID which under the cursor this way cursorID = win32gui.WindowFromPoint(win32gui.GetCursorPos()) their is function called GetWindowText I tried to use but it doesn't work in most of the time someone know a way to do this? thank you! One app that might be of help with your endeavors is called AutoIt (http://www.autoitscript.com/autoit3/) This suite of apps has a nice window browser, which shows most (if mot all) information available from a Windows window. Sometimes not all text in a window is available, depending on the window. It even comes with a COM component, so it can be scripted from Python... No affiliation, other than a contented user. Duane -- http://mail.python.org/mailman/listinfo/python-list
Re: Encrypted Logging in python
On Jan 9, 8:02 am, koranth...@gmail.com wrote: Also, what I am asking is a generic option in logging - which can help the adoption of the logging framework in even closed source systems. It is not just about security - just that a closed source company might be much more comfortable in using the system if crypt is there. Python is an open source project. Many people that read this list don't like closed source code too much and are not willing to invest time to work in features like this. You might get lucky and somebody that is interested in the topic might give you some tips. -- http://mail.python.org/mailman/listinfo/python-list
Python Apache Handler
Does anyone have any good examples, or links thereto for using python as an Apache handler? And I should qualify all of this by saying I'm a python newbie, and while having experience with Apache, I've never done anything outside whats in the box . What I'm looking for is how one might use Python not from the CGI/ presentation side but more on the backend...i.e. for each page Apache serves up examine the request and update some headers, or add a cookie to the response. Or possibly use Python for writing a custom Apache logger. I've searched the web but typically end up with pages for mod_python and writing CGI scripts. And if you feel this is better posted in an Apache group vs. here, let me apologize up front. Thanks -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Imaging Library and textmate
On Jan 9, 2009, at 2:49 AM, bilgin arslan wrote: Hello, I am a beginner in python and I am trying to create image files that contain lines from a text file. I am trying to do this with PIL, which seems like a suitable tool. I have a copy of TextMate(1.5.8) and I run Macosx 10.5.6 The problem is, even though I installed PIL correctly (I get no errors from import Image in IDLE or in terminal), I can't get TextMate to import the module. I keep getting ImportError: No module named Image error. I tried reloading TextMate's bundles but that did not work either. I use TextMate but I don't know what you mean when you say you can't get TM to import a module. Can you give a little more context? There was a similar thread in this list with textmate but I can't understand how that issue was solved in the end. link? bye Philip -- http://mail.python.org/mailman/listinfo/python-list
Re: win32gui
thank you I'm checking autoit documentation... -- http://mail.python.org/mailman/listinfo/python-list
Re: BadZipfile file is not a zip file
On Jan 9, 3:16 am, Steven D'Aprano st...@remove-this- cybersource.com.au wrote: The full signature of ZipFile is: ZipFile(file, mode=r, compression=ZIP_STORED, allowZip64=True) Try passing compression=zipfile.ZIP_DEFLATED and/or allowZip64=False and see if that makes any difference. Those arguments didn't make a difference in my case. The zip format does support alternative compression methods, it's possible that this particular file uses a different sort of compression which Python doesn't deal with. What would cause a zip file to not have a table of contents? What makes you think it doesn't have one? Because when I search for the file is not a zip file error in zipfile.py, there is a function that checks for a table of contents. Tho it looks like there are other ideas in this thread about what might cause that error... I'll keep reading... -- http://mail.python.org/mailman/listinfo/python-list
Re: BadZipfile file is not a zip file
On Jan 9, 3:46 am, Carl Banks pavlovevide...@gmail.com wrote: The zipfile format is kind of brain dead, you can't tell where the end of the file is supposed to be by looking at the header. If the end of file hasn't yet been reached there could be more data. To make matters worse, somehow zip files came to have text comments simply appended to the end of them. (Probably this was for the benefit of people who would cat them to the terminal.) Anyway, if you see something that doesn't adhere to the zipfile format, you don't have any foolproof way to know if it's because the file is corrupted or if it's just an appended comment. Most zipfile readers use a heuristic to distinguish. Python's zipfile module just assumes it's corrupted. The following post from a while back gives a solution that tries to snip the comment off so that zipfile module can handle it. It might help you out. http://groups.google.com/group/comp.lang.python/msg/c2008e48368c6543 Carl Banks Thanks Carl. I tried Scott's getzip() function yesterday... I stumbled upon it in my searches. It didn't seem to help in my case, though it did produce a different error: ValueError, substring not found. Not sure what that means. -- http://mail.python.org/mailman/listinfo/python-list
struct unpack to pre-allocated array?
Is there any way to struct.unpack or struct.unpack_from into an existing array.array or similar structure? I am unpacking file data in a loop and i was hoping to find something that performs better than simply unpacking into a new tuple each iteration. Thanks in advance, Rich -- http://mail.python.org/mailman/listinfo/python-list
Re: BadZipfile file is not a zip file
On Fri, Jan 9, 2009 at 9:05 AM, webcomm rya...@gmail.com wrote: On Jan 9, 3:46 am, Carl Banks pavlovevide...@gmail.com wrote: The zipfile format is kind of brain dead, you can't tell where the end of the file is supposed to be by looking at the header. If the end of file hasn't yet been reached there could be more data. To make matters worse, somehow zip files came to have text comments simply appended to the end of them. (Probably this was for the benefit of people who would cat them to the terminal.) Anyway, if you see something that doesn't adhere to the zipfile format, you don't have any foolproof way to know if it's because the file is corrupted or if it's just an appended comment. Most zipfile readers use a heuristic to distinguish. Python's zipfile module just assumes it's corrupted. The following post from a while back gives a solution that tries to snip the comment off so that zipfile module can handle it. It might help you out. http://groups.google.com/group/comp.lang.python/msg/c2008e48368c6543 Carl Banks Thanks Carl. I tried Scott's getzip() function yesterday... I stumbled upon it in my searches. It didn't seem to help in my case, though it did produce a different error: ValueError, substring not found. Not sure what that means. -- http://mail.python.org/mailman/listinfo/python-list This is a ticket about another issue or 2 with invalid zipfiles that the zipfile module won't load, but that other tools will compensate for: http://bugs.python.org/issue1757072 -- http://mail.python.org/mailman/listinfo/python-list
Re: Implementing file reading in C/Python
On Jan 9, 8:48 am, Johannes Bauer dfnsonfsdu...@gmx.de wrote: No - and I've not known there was a profiler yet have found anything meaningful (there seems to be an profiling C interface, but that won't get me anywhere). Is that a seperate tool or something? Could you provide a link? Thanks, Kind regards, Johannes It is part of the python standard library: http://docs.python.org/library/profile.html -- http://mail.python.org/mailman/listinfo/python-list
Re: why cannot assign to function call
ru...@yahoo.com wrote: a = array (1,2,3) b = a a[1] = 4 print b C, C++, VBA, Fortran, Perl: 1, 2, 3 Python: 1, 4, 3 You are mistaken I don't think so. See http://groups.google.com/group/comp.lang.python/msg/f99d5a0d8f869b96 The code I quoted there was tested. In the C/C++ case, array-to-pointer coercion confuses the issue so I embedded the array in a struct which is more like an object. No, that's cheating (IMHO). Structs used directly (rather than via pointers) are the odd beast, and while they're certainly possible in C, they are far from the normal idiom. And certainly embedding an array in a struct just to force it to be copied, avoiding the standard reference semantics, is an arbitrary trick. I never claimed that you *couldn't* have copy semantics in C; you can do almost anything you want in C (or C++). But the *normal* usage of an array is via a pointer, in which case the semantics are exactly the same as in Python, Java, REALbasic, .NET, etc. (Keep in mind my point was not to show the behavior of arrays, but to show that several common languages *do not* use Python's *all* names are references model -- though of course this does not preclude their having some Python-like assignments since they all have some way of doing references.) Ah. OK then, I guess I missed you're point. You're absolutely right; many languages have both reference types and value types. Python is a bit unusual in that it has only reference types. I would have picked a different example to illustrate that, but it's true nonetheless. Best, - Joe -- http://mail.python.org/mailman/listinfo/python-list
Re: sftp with no password from python
On 8 Jan, 18:49, Mike Hjorleifsson mhjorleifs...@gmail.com wrote: On Jan 8, 10:39 am, loial jldunn2...@googlemail.com wrote: Is it possible to usesftpwithout a password from python? Yes you can use keys you preestablish between the server and client so you dont need passwords, i do this on all my servers then lock off the ability to accept passwords at all, this way no one can dictionary attack my ssh servers. Thanks...do you have any python examples of using sftp? -- http://mail.python.org/mailman/listinfo/python-list
Re: BadZipfile file is not a zip file
On Jan 9, 5:42 am, John Machin sjmac...@lexicon.net wrote: And here's a little gadget that might help the diagnostic effort; it shows the archive size and the position of all the magic PKnn markers. In a normal uncommented archive, EndArchive_pos + 22 == archive_size. I ran the diagnostic gadget... archive size is 69888 FileHeader at 0 CentralDir at 43796 EndArchive at 43846 -- http://mail.python.org/mailman/listinfo/python-list
Re: BadZipfile file is not a zip file
On Jan 9, 10:14 am, Chris Mellon arka...@gmail.com wrote: This is a ticket about another issue or 2 with invalid zipfiles that the zipfile module won't load, but that other tools will compensate for: http://bugs.python.org/issue1757072 Hmm. That's interesting. Are there other tools I can use in a python script that are more forgiving? I am using the zipfile module only because it seems to be the most widely used. Are other options in python likely to be just as unforgiving? Guess I'll look and see... -- http://mail.python.org/mailman/listinfo/python-list
Re: Implementing file reading in C/Python
Marc 'BlackJack' Rintsch wrote: On Fri, 09 Jan 2009 04:04:41 +0100, Johannes Bauer wrote: As this was horribly slow (20 Minutes for a 2GB file) I coded the whole thing in C also: Yours took ~37 minutes for 2 GiB here. This just ~15 minutes: #!/usr/bin/env python from __future__ import division, with_statement import os import sys from collections import defaultdict from functools import partial from itertools import imap def iter_max_values(blocks, block_count): for i, block in enumerate(blocks): histogram = defaultdict(int) for byte in block: histogram[byte] += 1 yield max((count, byte) for value, count in histogram.iteritems())[1] [snip] Would it be faster if histogram was a list initialised to [0] * 256? -- http://mail.python.org/mailman/listinfo/python-list
Re: Extending Python with C or C++
Thomas Heller thel...@python.net wrote: Nick Craig-Wood schrieb: Thomas Heller thel...@python.net wrote: Nick Craig-Wood schrieb: Interesting - I didn't know about h2xml and xml2py before and I've done lots of ctypes wrapping! Something to help with the initial drudge work of converting the structures would be very helpful. ( http://pypi.python.org/pypi/ctypeslib/ ) I gave it a quick go and it worked fine. I had to edit the XML in one place to make it acceptable (removing a u from a hex number). If you are using a recent version of gccxml, then you should use the ctypeslib-gccxml-0.9 branch of ctypeslib instead of the trunk. (I should really merge the gccxml-0.9 branch into the trunk;-) If you are already using the branch and the XML file is not accepted, then could you please provide a short C code snippet that reproduces the problem so that I can fix it? I'm using gccxml from debian testing 0.9.0+cvs20080525-1 which I guess doesn't have the code from the branch in. I meant the branch in the repository where ctypeslib lives in. Anyway, it doesn't matter anymore since I merged that branch into the ctypeslib trunk. Now the problem with the 'u' suffix that you mentioned should be fixed, and I also made a quick change so that the sized integer types from stdint.h are generated correctly. So, please update your ctypeslib installation and trey again;-) I gave it a go and I can report success on both counts! Well done and thank you. -- Nick Craig-Wood n...@craig-wood.com -- http://www.craig-wood.com/nick -- http://mail.python.org/mailman/listinfo/python-list
Re: Implementing file reading in C/Python
On Jan 9, 6:48 am, Johannes Bauer dfnsonfsdu...@gmx.de wrote: mk schrieb: The factor of 30 indeed does not seem right -- I have done somewhat similar stuff (calculating Levenshtein distance [edit distance] on words read from very large files), coded the same algorithm in pure Python and C++ (using linked lists in C++) and Python version was 2.5 times slower. Yup, that was about what I had expected (and what I could well live with, it's a tradeoff). The rule-of-thumb I use is that Python is generally 5 to 50 times slower than C. It is considered blasphemy to say it in this group, but Python is slow. It does of course have many compensating advantages that make using it advantageous when runtime speed is not of primary importance. -- http://mail.python.org/mailman/listinfo/python-list
Re: why cannot assign to function call
Aaron Brady wrote:
Possible compromise. You can think of functions as mutation-only.
You pass the object, and it gets a new (additional) name. The old
name doesn't go in. /compromise
That's correct. The reference itself is passed in, not the variable (or
expression) that held or generated the reference in the calling code.
This is no different from, in C, passing an integer:
void foo(int bar) {
bar = 42;
}
int baz = 0;
foo(baz);
This doesn't change baz because, speaking precisely, baz wasn't passed
to foo -- only the *value* of baz (i.e. 0) was passed to foo. Within
foo, that value was stored in bar. Assigning a new value to bar does
not affect foo.
It's the exact same thing when the value happens to be a reference to an
object:
typedef SomeClass* SomeClassPtr;
void foo(SomeClassPtr bar) {
bar = new SomeClass();
}
SomeClassPtr baz = NULL;
foo(baz);
Again, we're not passing baz into foo; we're passing the *value* of baz
(i.e. NULL) into foo. That value is stored in bar within foo, and when
we assign a new value (a reference to a freshly minted SomeClass object)
into bar, of course it doesn't affect baz.
Regardless, IMO, references don't add any explanatory power; they just
make you feel cocky that you know what they are.
Nonsense. They are the simple and clear explanation of what's going on.
M: If 'fun()' returned a reference, you would be able to assign to it.
m: You can't assign to it.
C: It doesn't return a reference.
C is false because M is false (at least, in the way I believe you mean
it). Or, more precisely, both M and m are nonsensical; what does it
mean to assign to a reference? It makes no sense. What would it mean
to assign to 42?
You don't assign to references any more than you assign to integers or
assign to strings or assign to None. Those are all values, and you
don't assign to values -- you assign to variables. Assign means to
give a new value to a variable, i.e. to let (or cause) a variable to
have a new value. (Ye olde BASIC even used the LET keyword to indicate
this, e.g. LET X = 42.) Speaking casually, we don't always make this
distinction, but I think precision is needed here.
So, I see two ways to make sense of your argument:
M1: If 'fun()' returned a variable, you would be able to assign to it.
m1: You can't assign to it.
C1: It doesn't return a variable.
This is true. (Technically, instead of variable, we should say LValue
here -- there are things slightly more complex than simple variables
that can serve as the left-hand side of an assignment. So replace
variable with lvalue above if you prefer.)
Or, the other way some may see it is:
M2: If 'fun()' returned a reference, you might be able to mutate the
object that refers to.
m2: You can sometimes mutate the object it refers to.
C2: 'fun()' returns a reference.
This is true (though the logic is flawed, but fixable).
-- Why can't I assign to a function call?
-- Python variables are references only.
-- Ok, why can't I assign to a function call?
You're right, Python variables are references only has nothing to do
with it. In a language where the only data type were integer, you
wouldn't be able to assign to a function call either.
You can't assign to a function call because a function call is not
itself an lvalue, and it doesn't return an lvalue. That's just not
something you can get for free from the type model; it's an extra
feature that would have to be built into the language somehow, and
Python doesn't have it.
If assignment were an operator rather than a statement, and could be
overridden in a class via some specially-named method -- or, for that
matter, if the assignment statement looked for such a method when it
finds an object reference on the left-hand side -- then any object could
be an lvalue, and you COULD (in some cases) assign to the result of a
function. But it's not and it doesn't.
Best,
- Joe
--
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Re: Python 2.6 fails on compiling Bug report
Hi! I didn't wanted to post 11.000 Lines here, so I uploaded it here: http://rapidshare.com/files/181425216/config.log.html -- http://mail.python.org/mailman/listinfo/python-list
Re: Creating new instances of subclasses.
Thanks for the solutions everyone! I'm not sure which I'll end up
using, but I think I've got a better grasp of the problem now.
Cool stuff.
Cheers,
Cliff
On Thu, 2009-01-08 at 06:52 -0800, Paul McGuire wrote:
On Jan 7, 12:00 pm, Paul McGuire pt...@austin.rr.com wrote:
On Jan 7, 10:38 am, J. Cliff Dyer j...@unc.edu wrote:
I want to be able to create an object of a certain subclass, depending
on the argument given to the class constructor.
I have three fields, and one might need to be a StringField, one an
IntegerField, and the last a ListField. But I'd like my class to
delegate to the proper subclass automatically, so I can just do:
f1 = Field('abc')
f2 = Field('123')
f3 = Field('D,E,F')
O-O is not always the solution to every problem. Since inheritance is
getting in your way, try using a class-level factory method. Instead
of using the Field constructor, use a staticmethod of Field, something
like:
@staticmethod
def make_Field(a)
if is_list(a):
return ListField(a)
elif is_integer(a):
return IntegerField(a)
else:
return StringField(a)
and then get rid of all those __new__ methods, too.
-- Paul
After looking this over a bit more, I decided I didn't like make_Field
having to know the criteria for creating the different subclasses, but
wanted to put the smarts into the subclasses themselves. Here is an
excerpt that shows this working:
class Field(object):
def __init__(self, input):
super(Field, self).__init__(input)
self.data = input
@staticmethod
def make_Field(a):
subs = (ListField, IntegerField, StringField)
ret = None
for cls in subs:
try:
ret = cls(a)
except TypeError:
continue
else:
break
return ret
class IntegerField(Field):
def __new__(cls, a):
if not is_integer(a):
raise TypeError()
return Field.__new__(cls, a)
...
ListField has a similar __new__ method, and StringField just creates
the object, with no validation.
make_Field still has to know what order to list the subclasses in
(StringField is the most permissive, and so must come last in the list
of subclasses), but the specific type tests are moved into the
subclasses, which is a more appropriate place I think.
-- Paul
--
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--
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Re: why cannot assign to function call
ru...@yahoo.com ru...@yahoo.com wrote: As a side comment (because it always bugs me when I read this, even though I read it in very authoritative sources), ISTM that C passes everything by value except arrays; they are passed by reference (by passing a pointer to the array by value.) Admittedly, the close relationship between arrays and pointers makes it easy conflate them. Arrays are distinctly second-class citizens in C. Basically, in C, arrays aren't passed at all but there's some syntactic sugar so you can squint and con yourself that they're passed by reference. If you try to pass an array, the array name immediately decays to a pointer, and the pointer gets passed instead -- by value. The corresponding function parameter must be a pointer to an approrpriate kind of thing, though you're allowed to write []s to confuse yourself if you like -- T D[] in a function parameter declaration means precisely the same as T *D -- to the extent that D has type T **D and so on. -- [mdw] -- http://mail.python.org/mailman/listinfo/python-list
Guaranteeing an n-byte data type?
Hello all, I'm trying to use sockets to implement a pre-defined network protocol that requires that I send messages of exactly a certain number of bytes. In Python, integer values are represented as 4 bytes each (AFAIK.) However I don't want to always send 4 bytes: sometimes I want to send one byte, or 11 bytes, or 33 bytes, or any other permutation that's not a multiple of 4. It seems to make the most sense to use one-byte data members and concatenate them before sending. This is reasonably easy in C (thanks to the uint8_t data type), but with Python I'm not sure how I'd implement it. The send() method in the socket module will take any kind of data, but you can't specify the number of bytes you want to send, so there's no guarantee as to how many you're actually sending (particularly if you're sending a value that's regarded in Python as a long integer - who knows how that data is actually represented in memory behind the scenes!) Perhaps since I'm trying to perform low-level operations, Python is simply the wrong tool for this job. However, I'd very much like to write this implementation in Python for sake of quick implementation and testing. Cheers, Evan -- http://mail.python.org/mailman/listinfo/python-list
Re: why cannot assign to function call
Joe Strout wrote:
Aaron Brady wrote:
Possible compromise. You can think of functions as mutation-only.
You pass the object, and it gets a new (additional) name. The old
name doesn't go in. /compromise
That's correct. The reference itself is passed in, not the variable (or
expression) that held or generated the reference in the calling code.
This is no different from, in C, passing an integer:
void foo(int bar) {
bar = 42;
}
int baz = 0;
foo(baz);
This doesn't change baz because, speaking precisely, baz wasn't passed
to foo -- only the *value* of baz (i.e. 0) was passed to foo. Within
foo, that value was stored in bar. Assigning a new value to bar does
not affect foo.
It's the exact same thing when the value happens to be a reference to an
object:
typedef SomeClass* SomeClassPtr;
void foo(SomeClassPtr bar) {
bar = new SomeClass();
}
SomeClassPtr baz = NULL;
foo(baz);
Again, we're not passing baz into foo; we're passing the *value* of baz
(i.e. NULL) into foo. That value is stored in bar within foo, and when
we assign a new value (a reference to a freshly minted SomeClass object)
into bar, of course it doesn't affect baz.
Regardless, IMO, references don't add any explanatory power; they just
make you feel cocky that you know what they are.
Nonsense. They are the simple and clear explanation of what's going on.
M: If 'fun()' returned a reference, you would be able to assign to it.
m: You can't assign to it.
C: It doesn't return a reference.
C is false because M is false (at least, in the way I believe you mean
it). Or, more precisely, both M and m are nonsensical; what does it
mean to assign to a reference? It makes no sense. What would it mean
to assign to 42?
You don't assign to references any more than you assign to integers or
assign to strings or assign to None. Those are all values, and you
don't assign to values -- you assign to variables. Assign means to
give a new value to a variable, i.e. to let (or cause) a variable to
have a new value. (Ye olde BASIC even used the LET keyword to indicate
this, e.g. LET X = 42.) Speaking casually, we don't always make this
distinction, but I think precision is needed here.
So, I see two ways to make sense of your argument:
M1: If 'fun()' returned a variable, you would be able to assign to it.
m1: You can't assign to it.
C1: It doesn't return a variable.
This is true. (Technically, instead of variable, we should say LValue
here -- there are things slightly more complex than simple variables
that can serve as the left-hand side of an assignment. So replace
variable with lvalue above if you prefer.)
Or, the other way some may see it is:
M2: If 'fun()' returned a reference, you might be able to mutate the
object that refers to.
m2: You can sometimes mutate the object it refers to.
C2: 'fun()' returns a reference.
This is true (though the logic is flawed, but fixable).
-- Why can't I assign to a function call?
-- Python variables are references only.
-- Ok, why can't I assign to a function call?
You're right, Python variables are references only has nothing to do
with it. In a language where the only data type were integer, you
wouldn't be able to assign to a function call either.
You can't assign to a function call because a function call is not
itself an lvalue, and it doesn't return an lvalue. That's just not
something you can get for free from the type model; it's an extra
feature that would have to be built into the language somehow, and
Python doesn't have it.
If assignment were an operator rather than a statement, and could be
overridden in a class via some specially-named method -- or, for that
matter, if the assignment statement looked for such a method when it
finds an object reference on the left-hand side -- then any object could
be an lvalue, and you COULD (in some cases) assign to the result of a
function. But it's not and it doesn't.
Pretty soon you guys will have me believing Python doesn't work ...
regards
Steve
--
Steve Holden+1 571 484 6266 +1 800 494 3119
Holden Web LLC http://www.holdenweb.com/
--
http://mail.python.org/mailman/listinfo/python-list
Re: Guaranteeing an n-byte data type?
Evan Jones wrote: Hello all, I'm trying to use sockets to implement a pre-defined network protocol that requires that I send messages of exactly a certain number of bytes. In Python, integer values are represented as 4 bytes each (AFAIK.) However I don't want to always send 4 bytes: sometimes I want to send one byte, or 11 bytes, or 33 bytes, or any other permutation that's not a multiple of 4. It seems to make the most sense to use one-byte data members and concatenate them before sending. This is reasonably easy in C (thanks to the uint8_t data type), but with Python I'm not sure how I'd implement it. The send() method in the socket module will take any kind of data, but you can't specify the number of bytes you want to send, so there's no guarantee as to how many you're actually sending (particularly if you're sending a value that's regarded in Python as a long integer - who knows how that data is actually represented in memory behind the scenes!) Perhaps since I'm trying to perform low-level operations, Python is simply the wrong tool for this job. However, I'd very much like to write this implementation in Python for sake of quick implementation and testing. The send() method takes a bytestring argument (class str in Python 2.x, class bytes in Python 3.x), which is a string of 8-bit characters (1 byte per character). Just build your bytestring and then send it (actually it's better to use sendall() because send() isn't guaranteed to send all the bytes in one call). -- http://mail.python.org/mailman/listinfo/python-list
Re: why cannot assign to function call
On Fri, 09 Jan 2009 08:30:46 -0700, Joe Strout wrote:
That's correct. The reference itself is passed in, not the variable (or
expression) that held or generated the reference in the calling code.
This is no different from, in C, passing an integer:
void foo(int bar) {
bar = 42;
}
int baz = 0;
foo(baz);
This doesn't change baz because, speaking precisely, baz wasn't passed
to foo -- only the *value* of baz (i.e. 0) was passed to foo.
We can check whether bar and baz are the same thing, by printing their
addresses:
#includestdio.h
void foo(int bar) {
printf(\n The address of bar is %p , bar);
bar = 42;
}
int main() {
int baz = 0;
printf(\n The address of baz is %p , baz);
foo(baz);
return 0;
}
When I do this, I get:
The address of baz is 0xbfa72870
The address of bar is 0xbfa72850
So we can agree that baz and bar are different entities. Now, would
anyone like to take a small wager on what the equivalent code in CPython
would print?
def foo(bar):
print The address of bar is %s % id(bar)
bar = 42
baz = 0
print The address of baz is %s % id(baz)
foo(baz)
When I execute this, I get
The address of baz is 143599468
The address of bar is 143599468
Python doesn't do the same thing as C. It actually passes the same value
to the function, without copying it.
Why oh why do you keep insisting that Python is no different from C?
Let's try one more. In C:
#include stdio.h
#include stdlib.h
struct record {
int x;
};
void mutate(struct record bar) {
printf(\n The address of bar is %p , bar);
bar.x = 0;
printf(\n Inside: %d , bar.x);
}
struct record baz;
int main(void) {
baz.x = 1;
printf(\n The address of baz is %p , baz);
printf(\n Before: %d , baz.x);
mutate(baz);
printf(\n After: %d , baz.x);
return 0;
}
gives output:
The address of baz is 0x80496fc
Before: 1
The address of bar is 0xbfb8f980
Inside: 0
After: 1
We can clearly see that baz and bar are different entities, and changes
made to bar inside the function don't affect baz.
A Python equivalent:
class struct: pass
def mutate(bar):
print The address of bar is %d % id(bar)
bar.x = 0;
print Inside: %d % bar.x
baz = struct()
baz.x = 1
print The address of baz is %d % id(baz)
print Before: %d % baz.x
mutate(baz)
print After: %d % baz.x
which gives output:
The address of baz is 3085537420
Before: 1
The address of bar is 3085537420
Inside: 0
After: 0
Why oh why do you keep insisting that Python is no different from C?
--
Steven
--
http://mail.python.org/mailman/listinfo/python-list
Re: Guaranteeing an n-byte data type?
Evan Jones wrote: Hello all, I'm trying to use sockets to implement a pre-defined network protocol that requires that I send messages of exactly a certain number of bytes. In Python, integer values are represented as 4 bytes each (AFAIK.) However I don't want to always send 4 bytes: sometimes I want to send one byte, or 11 bytes, or 33 bytes, or any other permutation that's not a multiple of 4. It seems to make the most sense to use one-byte data members and concatenate them before sending. This is reasonably easy in C (thanks to the uint8_t data type), but with Python I'm not sure how I'd implement it. The send() method in the socket module will take any kind of data, but you can't specify the number of bytes you want to send, so there's no guarantee as to how many you're actually sending (particularly if you're sending a value that's regarded in Python as a long integer - who knows how that data is actually represented in memory behind the scenes!) Perhaps since I'm trying to perform low-level operations, Python is simply the wrong tool for this job. However, I'd very much like to write this implementation in Python for sake of quick implementation and testing. In Python 2 you'd use an 8-bit string - though as you surmise you need access to the conversions to and from the primitive data types. This is provided by the struct module. In Python 3 you'll use a bytes object; in 2.6 and onwards the bytes syntax can be used to refer to regular strings, to make portability easier (in Python 3, strings are Unicode by default). regards Steve -- Steve Holden+1 571 484 6266 +1 800 494 3119 Holden Web LLC http://www.holdenweb.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Guaranteeing an n-byte data type?
Evan Jones wrote: I'm trying to use sockets to implement a pre-defined network protocol that requires that I send messages of exactly a certain number of bytes. In Python, integer values are represented as 4 bytes each (AFAIK.) However I don't want to always send 4 bytes: sometimes I want to send one byte, or 11 bytes, or 33 bytes, or any other permutation that's not a multiple of 4. It seems to make the most sense to use one-byte data members and concatenate them before sending. In addition to previous suggestions, you should look at the struct and ctypes modules in the standard Python library. Both allow you to pack/unpack data to/from data structures with arbitrary layout and endianness. -- Grant Edwards grante Yow! I'm meditating on at the FORMALDEHYDE and the visi.comASBESTOS leaking into my PERSONAL SPACE!! -- http://mail.python.org/mailman/listinfo/python-list
Re: BadZipfile file is not a zip file
On Jan 9, 10:14 am, Chris Mellon arka...@gmail.com wrote: This is a ticket about another issue or 2 with invalid zipfiles that the zipfile module won't load, but that other tools will compensate for: http://bugs.python.org/issue1757072 Looks like I just need to do this to unzip with unix... from os import popen popen(unzip data.zip) That works for me. No idea why I didn't think of that earlier. I'm new to python but should have realized I could run unix commands with python. I had blinders on. Now I just need to get rid of some bad characters in the unzipped file. I'll start a new thread if I need help with that... -- http://mail.python.org/mailman/listinfo/python-list
Re: Implementing file reading in C/Python
On 2009-01-09, Johannes Bauer dfnsonfsdu...@gmx.de wrote: I've come from C/C++ and am now trying to code some Python because I absolutely love the language. However I still have trouble getting Python code to run efficiently. Right now I have a easy task: Get a file, If I were you, I'd try mmap()ing the file instead of reading it into string objects one chunk at a time. -- Grant Edwards grante Yow! I'm DESPONDENT ... I at hope there's something visi.comDEEP-FRIED under this miniature DOMED STADIUM ... -- http://mail.python.org/mailman/listinfo/python-list
Re: BadZipfile file is not a zip file
I missed the begining of this thread and so appologise if I'm repeating what someone else has said! I had a very similar problem with this error and it turned out it was due to me moving a file across a socket connection and either not reading it or writing it in the binary mode, ie open(filename, 'rb') or write(filename, 'wb'). This didn't make any difference on the linux machines (where the error didn't occur) but did on the windows machines and fixed the problem. Cheers, Wes On 09/01/2009, webcomm rya...@gmail.com wrote: On Jan 9, 10:14 am, Chris Mellon arka...@gmail.com wrote: This is a ticket about another issue or 2 with invalid zipfiles that the zipfile module won't load, but that other tools will compensate for: http://bugs.python.org/issue1757072 Looks like I just need to do this to unzip with unix... from os import popen popen(unzip data.zip) That works for me. No idea why I didn't think of that earlier. I'm new to python but should have realized I could run unix commands with python. I had blinders on. Now I just need to get rid of some bad characters in the unzipped file. I'll start a new thread if I need help with that... -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: Implementing file reading in C/Python
Johannes Bauer, I was about to start writing a faster version. I think with some care and Psyco you can go about as 5 times slower than C or something like that. To do that you need to use almost the same code for the C version, with a list of 256 ints for the frequencies, not using max() but a manual loop, not using itertools or generators, maybe splitting code in two functions to allow Psyco to optimize better, maybe using another array(...) for the frequences too. The data can be read into an array.array(B), and so on. But I think all this work is a waste of time. I like Python, but that C code, after some cleaning and polishing looks fine for this job. Of course there are other languages that may give you a little nicer code for this program, like D, and there may be ways to use numpy too to speed up the computation of the mode, but they don't look so much important this time. Bye, bearophile -- http://mail.python.org/mailman/listinfo/python-list
Re: Unexpected scientific notation
Mark Dickinson wrote:
On Jan 8, 1:00 am, Paul McNett p...@ulmcnett.com wrote:
It displays '3E+1' instead of '30.0'.
As I can't reproduce I'm looking for an idea brainstorm of what could be causing
this. What would be choosing to display such a normal number in scientific
notation?
Ideas?
[I thought I replied to this earlier, but the post isn't showing up.
So here it is again.]
LOL!
I suspect it's your use of the Decimal normalize() method that's
causing
this. Trailing zeros on Decimal instances are significant, so
Decimal('30.0'), Decimal('30') and Decimal('3E+1') are considered
distinct (though they all have the same value). The normalize method
strips all trailing zeros, turning Decimal('30.0') into Decimal('3E
+1').
One way to get around this is to add 0 after normalizing: this will
make sure that scientific notation is used only for very large
or small numbers, as usual.
Thank you for the insight. I believe the problem is with my use of normalize(), but I
still can't figure out why I can't reproduce the issue in my running app. But I can
see in the interpreter that printing Decimal(30.0).normalize() results in 3E+1.
Paul
--
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Re: Python Imaging Library and textmate
Hi Philip, I tried to install PIL with the directions given and it seemed to be ok. When I tried it with IDLE, import Image did not give an error and as far as I checked it seemed to be working. However, importing Image module in TextMate gives an error, saying that the module cannot be found for some strange reason. The code simply contains the line *import Image* in both cases On Jan 9, 2009, at 2:49 AM, bilgin arslan wrote: * Hello, ** I am a beginner in python and I am trying to create image files that ** contain ** lines from a text file. ** I am trying to do this with PIL, which seems like a suitable tool. I ** have a ** copy of TextMate(1.5.8) and I run Macosx 10.5.6 ** ** The problem is, even though I installed PIL correctly (I get no ** errors from ** import Image in IDLE or in terminal), I can't get TextMate to ** import the ** module. ** I keep getting ImportError: No module named Image error. ** I tried reloading TextMate's bundles but that did not work either. * I use TextMate but I don't know what you mean when you say you can't get TM to import a module. Can you give a little more context? * There was a similar thread in this list with textmate but I can't ** understand ** how that issue was solved in the end. * link? bye Philip -- http://mail.python.org/mailman/listinfo/python-list
Problem with -3 switch
Hi I'm getting started with Python and in order to get good habits for Python 3, i'd like to run my Python 2.6.1 with Python 3 warning mode. When i run python -3 and execute statement print 4 then i expect to see a warning because i've understood that this statement is not valid in Python 3 however no warning appears. Have is misunderstood something? I'm running Python on Windows Vista. thanks in advance! Aivar -- http://mail.python.org/mailman/listinfo/python-list
Re: Problem with -3 switch
On Fri, Jan 9, 2009 at 9:17 AM, Aivar Annamaa concat_na...@hotmail.com wrote: Hi I'm getting started with Python and in order to get good habits for Python 3, i'd like to run my Python 2.6.1 with Python 3 warning mode. When i run python -3 and execute statement print 4 then i expect to see a warning because i've understood that this statement is not valid in Python 3 however no warning appears. Have is misunderstood something? As was recently pointed out in a nearly identical thread, the -3 switch only points out problems that the 2to3 converter tool can't automatically fix. Changing print to print() on the other hand is easily fixed by 2to3. Cheers, Chris -- Follow the path of the Iguana... http://rebertia.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Apache Handler
Scooter wrote: Does anyone have any good examples, or links thereto for using python as an Apache handler? And I should qualify all of this by saying I'm a python newbie, and while having experience with Apache, I've never done anything outside whats in the box . What I'm looking for is how one might use Python not from the CGI/ presentation side but more on the backend...i.e. for each page Apache serves up examine the request and update some headers, or add a cookie to the response. I vaguely remembered that mod_python can do such things. Looking again it seems to be the case: http://www.modpython.org/live/current/doc-html/pyapi-filter.html Or possibly use Python for writing a custom Apache logger. [...] Maybe http://www.modpython.org/live/current/doc-html/dir-handlers-plh.html The documentation about this is a joke, though. Remember that you can write custom Apache loggers quite easily with piped logs: http://httpd.apache.org/docs/2.2/logs.html This looks roughly like this: CustomLog |/path/to/my_script.py common ## begin my_script.py ## import sys for line in sys.stdin: # do stuff ## end ## -- Gerhard -- http://mail.python.org/mailman/listinfo/python-list
Re: Unexpected scientific notation
On Jan 9, 5:16 pm, Paul McNett p...@ulmcnett.com wrote: Thank you for the insight. I believe the problem is with my use of normalize(), but I still can't figure out why I can't reproduce the issue in my running app. Me neither. In particular, I can't see how it could this output could come out of a locale.format call. Is it possible that your user is somehow seeing a direct str() or %s of a Decimal instance, rather than something that's been through a format method? Mark -- http://mail.python.org/mailman/listinfo/python-list
Re: Unexpected scientific notation
Paul McNett wrote: Mark Dickinson wrote: On Jan 8, 1:00 am, Paul McNett p...@ulmcnett.com wrote: It displays '3E+1' instead of '30.0'. As I can't reproduce I'm looking for an idea brainstorm of what could be causing this. What would be choosing to display such a normal number in scientific notation? Ideas? [I thought I replied to this earlier, but the post isn't showing up. So here it is again.] LOL! I'll clarify my LOL: Mark initially replied to me directly, to which I responded directly. Because he replied directly, I kept my response offline, too, not knowing if he had a special reason to discuss this offline instead of in public. Then he replied to the list, so I made a different response to the list. Anyway, thanks again Mark for your guidance. Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: Problem with -3 switch
As was recently pointed out in a nearly identical thread, the -3 switch only points out problems that the 2to3 converter tool can't automatically fix. Changing print to print() on the other hand is easily fixed by 2to3. Cheers, Chris I see. So i gotta keep my own discipline with print() then :) thanks! A -- http://mail.python.org/mailman/listinfo/python-list
Re: Implementing file reading in C/Python
Grant Edwards inva...@invalid wrote: On 2009-01-09, Johannes Bauer dfnsonfsdu...@gmx.de wrote: I've come from C/C++ and am now trying to code some Python because I absolutely love the language. However I still have trouble getting Python code to run efficiently. Right now I have a easy task: Get a file, If I were you, I'd try mmap()ing the file instead of reading it into string objects one chunk at a time. You've snipped the bit further on in that sentence where the OP says that the file of interest is 2GB. Do you still want to try mmap'ing it? -- \S -- si...@chiark.greenend.org.uk -- http://www.chaos.org.uk/~sion/ Frankly I have no feelings towards penguins one way or the other -- Arthur C. Clarke her nu becomeþ se bera eadward ofdun hlæddre heafdes bæce bump bump bump -- http://mail.python.org/mailman/listinfo/python-list
Re: Encrypted Logging in python
koranth...@gmail.com wrote: I was wondering if there is a mechanism to encrypt logging automatically in python. Python's standard library doesn't include any strong symmetric ciphers. But if you include for example a cryptographic module for AES, for example, it should be easy (I guess 10 lines of code, yes, the issue always is *which* 10 lines) to write a custom logger that encrypts using a hardcoded key. As others have said, this is not really secure, so you could just as well use something stupid like rot13 or base64 instead. The issue is as follows: (a) An application (after py2exe) will go as executable and there is no need for the user to know that it is written in python. If an exception occurs and it is logged, then the user can understand it is written in python. In 99.326 % of all cases, the answer is: so what? (b) A security threat. If an exception occurs, the code is seen by the user - and possibly be misused. Simply make the user not see the exception, but use a fallback exception handler that does whatever you want to. Write to a log file. Or write to an encrypted log file if you still think that helps. Base64 encoding somewhat helps - which is supported by logging module - but even that is not very secure. If there can be an option - wherein we send in the password and the logging is encrypted - it might be better. [...] As I said before, that should be trivial to program if you look up the documentation about the logging module. Just subclass FileHandler. And make sure your class is then used. That's probably the hardest part ;-) That all being said, I have one final advise: Your time is probably much better spent on *real* issues. -- Gerhard -- http://mail.python.org/mailman/listinfo/python-list
Re: Python Imaging Library and textmate
On Jan 9, 2009, at 12:19 PM, bilgin arslan wrote: Hi Philip, I tried to install PIL with the directions given and it seemed to be ok. When I tried it with IDLE, import Image did not give an error and as far as I checked it seemed to be working. However, importing Image module in TextMate gives an error, saying that the module cannot be found for some strange reason. I am still unclear on how you're importing Python modules via TextMate. It's a text editor, so even though I've used it for a couple of years, it's not at all obvious to me how you'd use it to import a Python module. I think I can help you, but to do so I need you to tell me *exactly* what menu items you're clicking on, e.g. Bundle/Python/ Run Script... The code simply contains the line *import Image* in both cases From what I can see in the PIL documentation, this wouldn't work. You'd need either this: from PIL import Image or this: import PIL.Image What am I missing? On Jan 9, 2009, at 2:49 AM, bilgin arslan wrote: * Hello, ** I am a beginner in python and I am trying to create image files that ** contain ** lines from a text file. ** I am trying to do this with PIL, which seems like a suitable tool. I ** have a ** copy of TextMate(1.5.8) and I run Macosx 10.5.6 ** ** The problem is, even though I installed PIL correctly (I get no ** errors from ** import Image in IDLE or in terminal), I can't get TextMate to ** import the ** module. ** I keep getting ImportError: No module named Image error. ** I tried reloading TextMate's bundles but that did not work either. * I use TextMate but I don't know what you mean when you say you can't get TM to import a module. Can you give a little more context? * There was a similar thread in this list with textmate but I can't ** understand ** how that issue was solved in the end. * link? bye Philip -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
