Call for diversity
The Python community is both incredibly diverse (Python 3.1's release manager was not yet eighteen years old) and incredibly lacking in diversity (none of the regular committers is a woman). Kirrily Robert gave a keynote at OSCON last week about women in Open Source, and I blogged about the lunchtime aftermath (if you're not familiar with the issues, I suggest making sure to follow all the links I included): http://www.artima.com/weblogs/viewpost.jsp?thread=263671 Thinking further, I believe that the Python community really needs to be more active in creating diversity. As my blog says, the first step is for us to admit that there is a problem. I believe that the next step is for us as a community to make a formal statement supporting diversity. I've created a new mailing list (divers...@python.org) to discuss the wording of a diversity statement, along with discussing diversity issues in general. I invite anyone interested in the subject of diversity to join the list -- even if you disagree that actively supporting diversity is needed, I would like a chance to convince you. http://mail.python.org/mailman/listinfo/diversity Please note that I believe that the Python community is generally welcoming and that the Python community would jump on anyone who behaved in an overtly prejudiced way (unlike some controversies in other communities). However, I think that we have also inherited the lack of diversity in Open Source as a whole, and I believe that taking a more active role in building diversity will build a more vibrant Python community. After all, as Kirrily pointed out, the more inclusive we are, the more people we have working on Python. I just started a new job this week, so I'm not going to be pushing this any time soon -- but I also feel that I need to throw this out so that other people can get involved if they want. -- Aahz (a...@pythoncraft.com) * http://www.pythoncraft.com/ Many customs in this life persist because they ease friction and promote productivity as a result of universal agreement, and whether they are precisely the optimal choices is much less important. --Henry Spencer -- http://mail.python.org/mailman/listinfo/python-announce-list Support the Python Software Foundation: http://www.python.org/psf/donations/
Re: bad certificate error
En Tue, 28 Jul 2009 09:02:40 -0300, Steven D'Aprano st...@remove-this-cybersource.com.au escribió: On Mon, 27 Jul 2009 23:16:39 -0300, Gabriel Genellina wrote: I don't see the point on fixing either the Python script or httplib to accomodate for an invalid server certificate... If it's just for internal testing, I'd use HTTP instead (at least until the certificate is fixed). In real life, sometimes you need to drive with bad brakes on your car, walk down dark alleys in the bad part of town, climb a tree without a safety line, and use a hammer without wearing goggles. We can do all these things. The OP has said that, for whatever reason, he needs to ignore a bad server certificate when connecting to HTTPS. Python is a language where developers are allowed to shoot themselves in the foot, so long as they do so in full knowledge of what they're doing. So, putting aside all the millions of reasons why the OP shouldn't accept an invalid certificate, how can he accept an invalid certificate? Yes, I understand the situation, but I'm afraid there is no way (that I know of). At least not without patching _ssl.c; all the SSL negotiation is handled by the OpenSSL library itself. I vaguely remember a pure Python SSL implementation somewhere that perhaps could be hacked to bypass all controls. But making it work properly will probably require a lot more effort than installing a self signed certificate in the server... -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
Re: Deprecated sets module with Python 2.6
En Tue, 28 Jul 2009 17:28:09 -0300, Virgil Stokes v...@it.uu.se escribió: I would appreciate help on correcting a problem when trying to create an *.exe file using py2exe via GUI2exe with Python 2.6.2. When using GUI2exe to create an *.exe I always get the following warning during the compile process: C:\Python26\lib\site-packages\py2exe\build_exe.py:16: DeprecationWarning: the sets module is deprecated import sets Note that build_exe.py is part of the py2exe package - the warning says that py2exe itself is importing a deprecated module, it's not in your code. and this results in the creation of an *.exe file that can not be executed. I don't think the warning above is related to your problem. Are you using the latest py2exe version? You may get more help in the py2exe mailing list; see http://www.py2exe.org/ -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
Re: open a file in python
On Jul 27, 2:55 pm, Diez B. Roggisch de...@nospam.web.de wrote:
jayshree wrote:
On Jul 27, 1:09 pm, Kushal Kumaran kushal.kumaran+pyt...@gmail.com
wrote:
On Mon, Jul 27, 2009 at 12:58 PM, jayshreejayshree06c...@gmail.com
wrote:
pk = open('/home/jayshree/my_key.public.pem' , 'rb').read()
Please tell me how to open a file placed in any directory or in same
directory.
After opening this file i want to use the contain (public key ) for
encryption
Does the code you've put into your message not read that file? If you
get an exception, copy-paste in the traceback message you get into
your mail.
--
kushal
try:
pk = open('/home/jayshree/my_key.public.pem' , 'rb').read()
except IOError:
print Error: can\'t find file or read data
else:
print reading from file successfully
Still no error it gives .what to do?
Erm - so it doesn't give an error - which means you have successfully opened
a file, and read it's contents.
So what exactly is your problem?
Diez- Hide quoted text -
- Show quoted text -
The Exact Problem is how to use the key containing by .pem file for
'encryption' .
can i print the contents of the .pem file
see http://stackoverflow.com/questions/1176864/problem-with-the-pem-file
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[no subject]
Hi, everyone Is there a python script can get a list of how much stack space each function in your program uses? ( the program is compiled by gcc) Any advice will be appreciate. -- http://mail.python.org/mailman/listinfo/python-list
Re: Deprecated sets module with Python 2.6
Diez B. Roggisch wrote: Virgil Stokes schrieb: I would appreciate help on correcting a problem when trying to create an *.exe file using py2exe via GUI2exe with Python 2.6.2. When using GUI2exe to create an *.exe I always get the following warning during the compile process: C:\Python26\lib\site-packages\py2exe\build_exe.py:16: DeprecationWarning: the sets module is deprecated import sets and this results in the creation of an *.exe file that can not be executed. On the other hand, if I use the same procedure (on the same Python code) with Python 2.5, there are no warnings and the *.exe works fine. The procedure used is that given in the example Less simpler one at http://code.google.com/p/gui2exe/wiki/GUI2ExeExamplesin Any suggestions, help, ... would be greatly appreciated. If you don't need your app running on python2.3 and earlier, just remove the sets-module and replace it with the builtin set. Of course Diez, this is a good suggestion. However, in this case the Python code that I am trying to convert into an *.exe file does not refer to sets directly; i.e, the use of this module is buried within a package that is imported (wxPython) which is not under my control. --V Diez -- http://mail.python.org/mailman/listinfo/python-list
about analyze object's stack usage
Hi, everyone Is there a python script can get a list of how much stack space each function in your program uses? ( the program is compiled by gcc) Any advice will be appreciate. -- http://mail.python.org/mailman/listinfo/python-list
Re: Deprecated sets module with Python 2.6
Virgil Stokes wrote: Diez B. Roggisch wrote: Virgil Stokes schrieb: I would appreciate help on correcting a problem when trying to create an *.exe file using py2exe via GUI2exe with Python 2.6.2. When using GUI2exe to create an *.exe I always get the following warning during the compile process: C:\Python26\lib\site-packages\py2exe\build_exe.py:16: DeprecationWarning: the sets module is deprecated import sets and this results in the creation of an *.exe file that can not be executed. On the other hand, if I use the same procedure (on the same Python code) with Python 2.5, there are no warnings and the *.exe works fine. The procedure used is that given in the example Less simpler one at http://code.google.com/p/gui2exe/wiki/GUI2ExeExamplesin Any suggestions, help, ... would be greatly appreciated. If you don't need your app running on python2.3 and earlier, just remove the sets-module and replace it with the builtin set. Of course Diez, this is a good suggestion. However, in this case the Python code that I am trying to convert into an *.exe file does not refer to sets directly; i.e, the use of this module is buried within a package that is imported (wxPython) which is not under my control. --V Diez Whoops, the reference to the module sets is in py2exe not wxPython. --V -- http://mail.python.org/mailman/listinfo/python-list
Re: If Scheme is so good why MIT drops it?
On Tuesday 28 July 2009 17:11:02 MRAB wrote: If you were a COBOL programmer, would you want to shout about it? :-) Hey don't knock it! - at the time, it was either COBOL or FORTRAN or some assembler or coding in hex or octal. And if code is data, where is Pythons ALTER statement? *Ducks* :-)Hendrik -- http://mail.python.org/mailman/listinfo/python-list
Re: python 3 and stringio.seek
On Jul 28, 2009, at 6:30 AM, Michele Petrazzo wrote:
Hi list,
I'm trying to port a my library to python 3, but I have a problem
with a
the stringio.seek:
the method not accept anymore a value like pos=-6 mode=1, but the
old
(2.X) version yes...
The error:
File /home/devel/Py3/lib/python3.0/io.py, line 2031, in seek
return self._seek(pos, whence)
IOError: Can't do nonzero cur-relative seeks
How solve this?
In Python 2, StringIO is a stream of bytes (non-Unicode characters).
In Python 3, StringIO is a stream of text (Unicode characters). In
the early development of Python 3 (and 3.1's _pyio), it was
implemented as a TextIOWrapper over a BytesIO buffer. TextIOWrapper
does not support relative seeks because it is difficult to map the
concept of a current position between bytes and the text that it
encodes, especially with variable-width encodings and other
considerations. Furthermore, the value returned from
TextIOWrapper.tell isn't just a file position but a cookie that
contains other data necessary to restore the decoding mechanism to the
same state. However, for the default encoding (utf-8), the current
position is equivalent to that of the underlying bytes buffer.
In Python 3, StringIO is implemented using an internal buffer of
Unicode characters. There is no technical reason why it can't support
relative seeks; I assume it does not for compatibility with the
original Python TextIOWrapper implementation (which is present in
3.1's _pyio, but not in 3.0).
Note that because of the different implementations, StringIO.tell()
(and seek) behaves differently for the C and Python implementations:
$ python3.1
import io, _pyio
s = io.StringIO('\u263A'); s.read(1), s.tell()
('☺', 1)
s = _pyio.StringIO('\u263A'); s.read(1), s.tell()
('☺', 3)
The end result seems to be that, for text streams (including
StreamIO), you *should* treat the value returned by tell() as an
opaque magic cookie, and *only* pass values to seek() that you have
obtained from a previous tell() call. However, in practice, it
appears that you *may* seek StringIO objects relatively by characters
using s.seek(s.tell() + n), so long as you do not use the
_pyio.StringIO implementation.
If what you actually want is a stream of bytes, use BytesIO, which may
be seeked (sought?) however you please.
I'm basing this all on my reading of the Python source (and svn
history), since it doesn't seem to be documented, so take it with a
grain of salt.
-Miles
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fast video encoding
Hi all, for a scientific application I need to save a video stream to disc for further post processing. My cam can deliver 8bit grayscale images with resolution 640x480 with a framerate up to 100Hz, this is a data rate of 30MB/s. Writing the data uncompressed to disc hits the data transfer limits of my current system and creates huge files. Therefore I would like to use video compression, preferably fast and high quality to lossless encoding. Final file size is not that important. Because of the hardware I am bound to WinXP. I already tried pymedia for encoding to mpeg2, however I only managed to get a framerate of about 30-40fps (on a 1.8GHz dual core). There is still room for improvements in my code, but before trying hard I want to ask for advices or other possibilities. I also found gstreamer with pygst python bindings, which seems to be more modern (and performant?) package than pymedia. I did not yet try it, especially since I didn't find a simple code example of how to use it for my use case. Can somebody give me a hint? I also found huffyuv or lagarith which is provided as a directshow codec for Windows. Can somebody give me a hint how to use a directshow codec with python? I am a novice with video encoding. I found that few codecs support gray scale images. Any hints to take advantage of the fact that I only have gray scale images? Thanks for any help Gregor -- http://mail.python.org/mailman/listinfo/python-list
Re: instead of depending on data = array('h') .. write samples 1 by 1 to w = wave.open(wav.wav, w)
'2+ wrote:
it says
Wave_write.writeframes(data)
will that mean
from array import array
is a must?
this does the job:
import oil
import wave
from array import array
a = oil.Sa()
w = wave.open(current.wav, w)
w.setnchannels(2)
w.setsampwidth(2)
w.setframerate(44100)
data = array('h')
for gas in range(44100 * 5):
a.breath()
r = int(32767 * (a.pulse(1) + a.pulse(2) + a.pulse(3)) / 3.0)
l = int(32767 * (a.pulse(4) + a.pulse(5) + a.pulse(6)) / 3.0)
data.append(r)
data.append(l)
w.writeframes(data.tostring())
w.close()
don't like array becoming so huge so tested this and it was also okay:
for gas in range(44100 * 5):
a.breath()
data = array('h')
r = int(32767 * (a.pulse(1) + a.pulse(2) + a.pulse(3)) / 3.0)
l = int(32767 * (a.pulse(4) + a.pulse(5) + a.pulse(6)) / 3.0)
data.append(r)
data.append(l)
w.writeframes(data.tostring())
but without array .. it becomes 15secs(3 times longer than was
intended to be) of wav file:
for gas in range(44100 * 5):
a.breath()
r = int(32767 * (a.pulse(1) + a.pulse(2) + a.pulse(3)) / 3.0)
l = int(32767 * (a.pulse(4) + a.pulse(5) + a.pulse(6)) / 3.0)
w.writeframes(hex(r))
w.writeframes(hex(l))
Doesn't it sound strange, too? You are writing bogus bytes to the file.
Compare:
import array
array.array(h, [42]).tostring()
'*\x00'
hex(42)
'0x2a'
Not only do they differ in length, the contents are different, too. If
you're unfamiliar with string escape codes, here's a way to see the bytes:
map(ord, array.array(h, [42]).tostring())
[42, 0]
map(ord, hex(42))
[48, 120, 50, 97]
should i just be happy with depennding on using array?
or is there a solution to make the last one work properly?
There is a way to make the last one work: use struct.pack(h, r) instead of
hex(r). I'm of course assuming that the first version does give you the
desired result. You should not continue before you have verified that.
I still recommend array for performance reasons. If memory usage is an issue
you can adopt a hybrid approach:
# untested
from itertools import islice
from array import array
def gen_data():
for gas in xrange(44100 * 5): # range -- xrange
a.breath()
r = int(32767 * (a.pulse(1) + a.pulse(2) + a.pulse(3)) / 3.0)
l = int(32767 * (a.pulse(4) + a.pulse(5) + a.pulse(6)) / 3.0)
yield r
yield l
data = gen_data()
N = 2**20
while True:
chunk = array('h')
chunk.extend(islice(data, N))
if not chunk:
break
w.writeframes(chunk.tostring())
This will limit the array size to 4N bytes.
Peter
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64-bit issues with dictionaries in Python 2.6
HI! Are there any known issues with dictionaries in Python 2.6 (not 2.6.2) when running on a 64-bit platform? A friend of mine experiences various strange problems with my web2ldap running with Python 2.6 shipped with openSUSE 11.1 x64. For me it seems some dictionary-based internal registries of web2ldap are not working. Yes, the next test would be to compile Python 2.6.2 from source... Any hint is appreciated. Ciao, Michael. -- http://mail.python.org/mailman/listinfo/python-list
idiom for list looping
hi clp. i want to get from here: nomi = [one, two, three] to here: 0 - one 1 - two 2 - three i found two ways: first way: for i in range(len(nomi)): print i, -, nomi[i] or second way: for (i, e) in enumerate(nomi): print i, -, e which one is better? is there a more pythonic way to do it? bye ps: m...@192.168.1.102:~/test$ python -V Python 2.3.4 m...@192.168.1.102:~/test$ uname -a Linux fisso 2.4.24 #1 Thu Feb 12 19:49:02 CET 2004 i686 GNU/Linux m...@192.168.1.102:~/test$ -- http://mail.python.org/mailman/listinfo/python-list
Re: idiom for list looping
To the best of my knowledge the second way is more pythonic - the first is a little too reminiscent of C. A couple of notes: - you don't need the parentheses around i, e - if you were going to use the first way it's better to use xrange instead of range for iteration -- David Roberts http://da.vidr.cc/ On Wed, Jul 29, 2009 at 19:02, superpollou...@example.net wrote: hi clp. i want to get from here: nomi = [one, two, three] to here: 0 - one 1 - two 2 - three i found two ways: first way: for i in range(len(nomi)): print i, -, nomi[i] or second way: for (i, e) in enumerate(nomi): print i, -, e which one is better? is there a more pythonic way to do it? bye ps: m...@192.168.1.102:~/test$ python -V Python 2.3.4 m...@192.168.1.102:~/test$ uname -a Linux fisso 2.4.24 #1 Thu Feb 12 19:49:02 CET 2004 i686 GNU/Linux m...@192.168.1.102:~/test$ -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: idiom for list looping
superpollo wrote: hi clp. i want to get from here: nomi = [one, two, three] to here: 0 - one 1 - two 2 - three i found two ways: first way: for i in range(len(nomi)): print i, -, nomi[i] or second way: for (i, e) in enumerate(nomi): print i, -, e which one is better? is there a more pythonic way to do it? 'enumerate' is the Pythonic solution. -- http://mail.python.org/mailman/listinfo/python-list
Re: Deprecated sets module with Python 2.6
What about this?
import warnings
warnings.simplefilter('ignore', DeprecationWarning)
import the_module_causing_the_warning
warnings.resetwarnings()
--- Giampaolo
http://code.google.com/p/pyftpdlib
http://code.google.com/p/psutil
--
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Re: idiom for list looping
superpollo wrote: for (i, e) in enumerate(nomi): print i, -, e Just to be random: print '\n'.join([%s - %s % (i, e) for i, e in enumerate(nomi)]) This has one advantage: only print once. So it's slightly faster if you have a list of a large amount. -- http://mail.python.org/mailman/listinfo/python-list
Re: idiom for list looping
Xavier Ho wrote: superpollo wrote: for (i, e) in enumerate(nomi): print i, -, e Just to be random: print '\n'.join([%s - %s % (i, e) for i, e in enumerate(nomi)]) This has one advantage: only print once. So it's slightly faster if you have a list of a large amount. Slightly shorter: print '\n'.join(%s - %s % p for p in enumerate(nomi)) :-) -- http://mail.python.org/mailman/listinfo/python-list
Re: idiom for list looping
On Wed, Jul 29, 2009 at 8:52 PM, MRAB pyt...@mrabarnett.plus.com wrote: Slightly shorter: print '\n'.join(%s - %s % p for p in enumerate(nomi)) :-) That's cool. Does that make the list a tuple? (not that it matters, I'm just curious!) I just tested for a list of 1000 elements (number in letters from 1 to 1000 code I wrote for doing project euler problem 17), and the join method is 0.1 seconds faster than the for loop! Woo!? ;p -- http://mail.python.org/mailman/listinfo/python-list
Re: idiom for list looping
MRAB wrote: Xavier Ho wrote: superpollo wrote: for (i, e) in enumerate(nomi): print i, -, e Just to be random: print '\n'.join([%s - %s % (i, e) for i, e in enumerate(nomi)]) This has one advantage: only print once. So it's slightly faster if you have a list of a large amount. Slightly shorter: print '\n'.join(%s - %s % p for p in enumerate(nomi)) :-) print '\n'.join(%s - %s % p for p in enumerate(nomi)) File stdin, line 1 print '\n'.join(%s - %s % p for p in enumerate(nomi)) ^ SyntaxError: invalid syntax print '\n'.join([%s - %s % p for p in enumerate(nomi)]) 0 - one 1 - two 2 - three help() Welcome to Python 2.3! This is the online help utility. ... ;-) bye -- http://mail.python.org/mailman/listinfo/python-list
idiom for list looping
Ack, sent to the wrong email again. On Wed, Jul 29, 2009 at 9:02 PM, superpollo u...@example.net wrote: print '\n'.join(%s - %s % p for p in enumerate(nomi)) File stdin, line 1 print '\n'.join(%s - %s % p for p in enumerate(nomi)) ^ SyntaxError: invalid syntax lol, I knew I shouldn't have trusted untested code! print '\n'.join([%s - %s % p for p in enumerate(nomi)]) 0 - one 1 - two 2 - three Yup.. but using a variable for the tuple itself was a good move though =P. -- http://mail.python.org/mailman/listinfo/python-list
Re: idiom for list looping
Xavier Ho wrote: On Wed, Jul 29, 2009 at 8:52 PM, MRAB pyt...@mrabarnett.plus.com mailto:pyt...@mrabarnett.plus.com wrote: Slightly shorter: print '\n'.join(%s - %s % p for p in enumerate(nomi)) :-) That's cool. Does that make the list a tuple? (not that it matters, I'm just curious!) I've just replaced the list comprehension with a generator expression. -- http://mail.python.org/mailman/listinfo/python-list
Re: idiom for list looping
On Wed, Jul 29, 2009 at 9:17 PM, MRAB pyt...@mrabarnett.plus.com wrote: I've just replaced the list comprehension with a generator expression. Oh, and that isn't in Python 2.3 I see. Generators are slightly newer, eh. Thanks! -- http://mail.python.org/mailman/listinfo/python-list
Re: Semaphore Techniques
John D Giotta jdgio...@gmail.com wrote: I'm looking to run a process with a limit of 3 instances, but each execution is over a crontab interval. I've been investigating the threading module and using daemons to limit active thread objects, but I'm not very successful at grasping the documentation. Is it possible to do what I'm trying to do and if so anyone know of a useful example to get started? If you want a simple, cross platform way of doing it, then bind each process to a different local tcp port. Make a list of 3 ports, and try binding to each port in turn. If you can't find a port to bind to then there are already 3 instances running. Something like this import socket PORTS = range(1,10003) lock_sock = None def lock_process(_locks = []): for port in PORTS: sock = socket.socket() try: sock.bind((localhost, port)) except socket.error, e: sock = None else: _locks.append(sock) break else: raise Exception(Too many instances of me running) for i in range(5): print Trying,i+1 lock_process() Which prints Trying 1 Trying 2 Trying 3 Trying 4 Traceback (most recent call last): File stdin, line 20, in module File stdin, line 16, in lock_process Exception: Too many instances of me running You could do the same thing with lock files also very easily... -- Nick Craig-Wood n...@craig-wood.com -- http://www.craig-wood.com/nick -- http://mail.python.org/mailman/listinfo/python-list
QFileDialog setFileMode blues
Heya, I am fairly new to Python and even newer to Qt. The problem is opening a Qt file dialog to select folders only. QFileDialog has a nice and dandy setFileMode() function just for that. The only trouble is that I cannot make it work. Last thing I've tried was something like this: self.fd = QtGui.QFileDialog() self.fd.setFileMode(self.fd.FileMode(4)) filename = self.fd.getOpenFileName() ..but it was fruitless. Any help? Tons of internets in return! -- http://mail.python.org/mailman/listinfo/python-list
Re: QFileDialog setFileMode blues
On Wed, 29 Jul 2009 04:35:42 -0700 (PDT), Rincewind spoo...@gmail.com wrote: Heya, I am fairly new to Python and even newer to Qt. The problem is opening a Qt file dialog to select folders only. QFileDialog has a nice and dandy setFileMode() function just for that. The only trouble is that I cannot make it work. Last thing I've tried was something like this: self.fd = QtGui.QFileDialog() self.fd.setFileMode(self.fd.FileMode(4)) filename = self.fd.getOpenFileName() ..but it was fruitless. Any help? Tons of internets in return! QFileDialog.getOpenFileName() is a static method that creates its own QFileDialog internally. It's not using the one you have created and configured. Phil -- http://mail.python.org/mailman/listinfo/python-list
Run pyc file without specifying python path ?
Hi, I wanted to make a python byte-code file executable, expecting to be able to run it without specifying python on the (Linux bash) command line. So, I wrote the following: [r...@vmlinux1 python]# cat test_pyc.py #!/usr/bin/env python print hello [r...@vmlinux1 python]# and made its pyc file executable: [r...@vmlinux1 python]# ls -ls test_pyc.pyc 4 -rwxr-xr-x 1 root root 106 Jul 29 14:22 test_pyc.pyc [r...@vmlinux1 python]# So, I see: [r...@vmlinux1 python]# file test_pyc.py* test_pyc.py: a python script text executable test_pyc.pyc: python 2.3 byte-compiled [r...@vmlinux1 python]# If I try to do the following, no problem: [r...@vmlinux1 python]# python test_pyc.pyc hello [r...@vmlinux1 python]# However, the following fails: [r...@vmlinux1 python]# ./test_pyc.pyc -bash: ./test_pyc.pyc: cannot execute binary file [r...@vmlinux1 python]# Is there a way to run a pyc file without specifying the python path ? Bye, Ron. -- http://mail.python.org/mailman/listinfo/python-list
Re: fast video encoding
On 7/29/2009 4:14 AM, gregorth wrote: Hi all, for a scientific application I need to save a video stream to disc for further post processing. My cam can deliver 8bit grayscale images with resolution 640x480 with a framerate up to 100Hz, this is a data rate of 30MB/s. Writing the data uncompressed to disc hits the data transfer limits of my current system and creates huge files. Therefore I would like to use video compression, preferably fast and high quality to lossless encoding. Final file size is not that important. Try googling realtime greyscale video codec... Because of the hardware I am bound to WinXP. There's always a way to run linux :p I already tried pymedia for encoding to mpeg2, however I only managed to get a framerate of about 30-40fps (on a 1.8GHz dual core). There is still room for improvements in my code, but before trying hard I want to ask for advices or other possibilities. I also found gstreamer with pygst python bindings, which seems to be more modern (and performant?) package than pymedia. I did not yet try it, especially since I didn't find a simple code example of how to use it for my use case. Can somebody give me a hint? Video encoding is not my specialty, but my recommendation here is to drop python because of its slow speed and work in c as much as possible. I also found huffyuv or lagarith which is provided as a directshow codec for Windows. Can somebody give me a hint how to use a directshow codec with python? Not me, sorry :( Never worked directly with directshow (no pun intended). I am a novice with video encoding. I found that few codecs support gray scale images. Any hints to take advantage of the fact that I only have gray scale images? Greyscale PNG or BMP compression. Thanks for any help Don't know if this counts as help, but you're welcome! Gregor Marcus -- http://mail.python.org/mailman/listinfo/python-list
Re: simple splash screen?
On 7/28/2009 11:58 PM, NighterNet wrote: I am trying to make a simple splash screen from python 3.1.Not sure where to start looking for it. Can any one help? Trying to make a splash screen for python? Or trying to do image processing in python? Marcus -- http://mail.python.org/mailman/listinfo/python-list
Re: Need help in passing a -c command argument to the interactive shell.
Bill bsag...@gmail.com wrote: On my windows box I type = c:\xpython -c import re The result is = c:\x In other words, the Python interactive shell doesn't even open. What am I doing wrong? I did RTFM at http://www.python.org/doc/1.5.2p2/tut/node4.html on argument passing, but to no avail. Why are you reading documentation for Python 1.5? There have been just a few releases since then. Try reading http://docs.python.org/using/cmdline.html instead, specifically the part about the -i command line option. Or you could just try python -? at a command prompt. -- Duncan Booth http://kupuguy.blogspot.com -- http://mail.python.org/mailman/listinfo/python-list
Re: about analyze object's stack usage
On 7/29/2009 3:51 AM, hch wrote: Is there a python script can get a list of how much stack space each function in your program uses? I don't think so. You could try raw reading of the memory from another thread using ctypes and pointers, but that would be madness. ( the program is compiled by gcc) If you're talking about a c program, almost certainly not. What you should do is just use gdb and disas each function and look at what it subtracts off of %esp at the third instruction in the function. I can explain it to you if you are not very experienced in gdb and assembly... Marcus -- http://mail.python.org/mailman/listinfo/python-list
Particle research opens door for new technology
Big uses for small particles will be explored at the annual Particle Technology Research Centre Conference at The University of Western Ontario July 9 and 10.more http://0nanotechnology0.blogspot.com/ -- http://mail.python.org/mailman/listinfo/python-list
Help with sql and python
Hello ! I have accont on myphpadmin on my server. I want to create one script in python. This script manage sql task from my sql server . How i make this in a simple way ? Thank you ! -- http://mail.python.org/mailman/listinfo/python-list
Re: Particle research opens door for new technology
Is this a spam? Why did you have to send it 4 times, and it's already in the past (July 9 and 10) ? Ching-Yun Xavier Ho, Technical Artist Contact Information Mobile: (+61) 04 3335 4748 Skype ID: SpaXe85 Email: cont...@xavierho.com Website: http://xavierho.com/ -- http://mail.python.org/mailman/listinfo/python-list
Working with platform.system()
Hi! I want to know how I can get different expected return values by platform.system() method. I want to sniff some systems (Linux, Windows, Mac, BSD, Solaris) and I don't know how I can check them correctly. Could you give me some expected return values that you know? Thanks in advance, Paulo Ricardo -- http://mail.python.org/mailman/listinfo/python-list
escaping characters in filenames
I wrote a script to process some files using another program. One thing I noticed was that both os.listdir() and os.path.walk() will return unescaped file names (ie: My File With Spaces Stuff instead of My\ File\ With\ Spaces\ \\ Stuff). I haven't had much success finding a module or recipe that escapes file names and was wondering if anyone could point me in the right direction. As an aside, the script is using subprocess.call() with the shell=True parameter. There isn't really a reason for doing it this way (was just the fastest way to write it and get a prototype working). I was wondering if Popen objects were sensitive to unescaped names like the shell. I intend to refactor the function to use Popen objects at some point and thought perhaps escaping file names may not be entirely necessary. Cheers -- http://mail.python.org/mailman/listinfo/python-list
Re: Semaphore Techniques
Carl Banks pavlovevide...@gmail.com (CB) wrote: CB On Jul 28, 3:15 pm, John D Giotta jdgio...@gmail.com wrote: I'm looking to run a process with a limit of 3 instances, but each execution is over a crontab interval. I've been investigating the threading module and using daemons to limit active thread objects, but I'm not very successful at grasping the documentation. Is it possible to do what I'm trying to do and if so anyone know of a useful example to get started? CB It seems like you want to limit the number of processes to three; the CB threading module won't help you there because it deals with threads CB within a single process. CB What I'd do is to simply run the system ps to see how many processes CB are running (ps is pretty versatile on most systems and can find CB specifically targeted processes like you program), and exit if there CB are already three. That will surely run into some race conditions. If the limit of 3 processes is soft then that wouldn't be a big deal, however. -- Piet van Oostrum p...@cs.uu.nl URL: http://pietvanoostrum.com [PGP 8DAE142BE17999C4] Private email: p...@vanoostrum.org -- http://mail.python.org/mailman/listinfo/python-list
Re: QFileDialog setFileMode blues
On Jul 29, 12:45 pm, Phil Thompson p...@riverbankcomputing.com wrote: On Wed, 29 Jul 2009 04:35:42 -0700 (PDT), Rincewind spoo...@gmail.com wrote: Heya, I am fairly new to Python and even newer to Qt. The problem is opening a Qt file dialog to select folders only. QFileDialog has a nice and dandy setFileMode() function just for that. The only trouble is that I cannot make it work. Last thing I've tried was something like this: self.fd = QtGui.QFileDialog() self.fd.setFileMode(self.fd.FileMode(4)) filename = self.fd.getOpenFileName() ..but it was fruitless. Any help? Tons of internets in return! QFileDialog.getOpenFileName() is a static method that creates its own QFileDialog internally. It's not using the one you have created and configured. Phil You are awesome, thanks! -- http://mail.python.org/mailman/listinfo/python-list
Re: escaping characters in filenames
J Kenneth King wrote: I wrote a script to process some files using another program. One thing I noticed was that both os.listdir() and os.path.walk() will return unescaped file names (ie: My File With Spaces Stuff instead of My\ File\ With\ Spaces\ \\ Stuff). I haven't had much success finding a module or recipe that escapes file names and was wondering if anyone could point me in the right direction. That's only necessary if you're building a command line and passing it as a string. As an aside, the script is using subprocess.call() with the shell=True parameter. There isn't really a reason for doing it this way (was just the fastest way to write it and get a prototype working). I was wondering if Popen objects were sensitive to unescaped names like the shell. I intend to refactor the function to use Popen objects at some point and thought perhaps escaping file names may not be entirely necessary. Pass the command line to Popen as a list of strings. -- http://mail.python.org/mailman/listinfo/python-list
SEC forms parsing
I am looking for any python examples that have written to parse SEC filings (Security Exchange Commission's EDGAR system),or just a pointer to best modules to use. -- http://mail.python.org/mailman/listinfo/python-list
Re: Very Strange Problem
Omer Khalid wrote:
Hi,
I am having a very strange problem with modifying a variable in a list
in my program. Here is the code:
# a list that contains dictionary objects
jobs = []
index=5
for each in range(index):
jobs.append({'v':0})
some_function(index):
if jobs[index]['v'] == 0:
# set it to 1
jobs[index]['v'] = 1
print Set to 1
else:
print Already set to 1
loop():
index=0
for each in range(len(jobs)):
some_function(index)
index +=1
Apparently, the jobs[index]['v'] never get updated in the some_function
but the print statement afterwards get printed...
What's really surprising is that there are no errors or exceptions and
my my program runs in a single thread...so i have been unable to explain
this behavior.
Any insight would be much appreciated!
Well, when I insert the missing 'def's in the function definitions, it
works for me.
--
http://mail.python.org/mailman/listinfo/python-list
Re: Compiling Python for uCLinux appliance?
On 2009-07-29, Diez B. Roggisch de...@nospam.web.de wrote: Gilles Ganault wrote: Hello I just got a small appliance based on a Blackfin CPU with 64MB RAM and 258MB NAND flash. Using the stock software, there's about 30MB of RAM left. Besides C/C++ and shel scripts, I was wondering if it were realistic to upload a few Python scripts in such a small appliance? The standard uclinux-dist comes with python, so it's pretty much just a question of memory. Asking on the uclinux mailing list will probably be more useful, but I would guess that 64MB would be plenty -- especially if use JFFS to put your root filesystem in flash instead of in RAM. Of course it depends entirely on what else you want to do with that RAM at the same time... Try check out the gumstix software repo. It comes with python, and thus some crosscompiling/build-instructions should be in there. IIRC, all you have to do is make menuconfig, go to the user apps page and check the Python box, and then make. It should just work. -- Grant Edwards grante Yow! I haven't been married at in over six years, but we visi.comhad sexual counseling every day from Oral Roberts!! -- http://mail.python.org/mailman/listinfo/python-list
Re: how to embed the python interpreter into web App (Mehndi, Sibtey)
Hi All I am trying to embed the python interpreter in to a web app but could not get the way, any one can suggest me how to do this. Thanks, Sibtey Mehdi This e-mail (and any attachments), is confidential and may be privileged. It may be read, copied and used only by intended recipients. Unauthorized access to this e-mail (or attachments) and disclosure or copying of its contents or any action taken in reliance on it is unlawful. Unintended recipients must notify the sender immediately by e-mail/phone delete it from their system without making any copies or disclosing it to a third person. Here's example: http://try-python.mired.org/ Contact with author of that website/webapp. Good luck. -- http://mail.python.org/mailman/listinfo/python-list
Re: Very Strange Problem
Ricardo Aráoz wrote:
MRAB wrote:
Omer Khalid wrote:
Hi,
I am having a very strange problem with modifying a variable in a
list in my program. Here is the code:
# a list that contains dictionary objects
jobs = []
index=5
for each in range(index):
jobs.append({'v':0})
some_function(index):
if jobs[index]['v'] == 0:
# set it to 1
jobs[index]['v'] = 1
print Set to 1
else:
print Already set to 1
loop():
index=0
for each in range(len(jobs)):
some_function(index)
index +=1
Apparently, the jobs[index]['v'] never get updated in the
some_function but the print statement afterwards get printed...
What's really surprising is that there are no errors or exceptions
and my my program runs in a single thread...so i have been unable to
explain this behavior.
Any insight would be much appreciated!
Well, when I insert the missing 'def's in the function definitions, it
works for me.
Hi Omer, what he is trying to convey in his rude manner is that you are
missing def in your function definitions. It is probably a beginners
mistake.
That is :
from some_function(index):
to def some_function(index):
from loop():
to def loop():
I have not tried your code so you should believe him when he states he
has actually run the code.
HTH
Omer says the print statement afterwards get printed, but the code
provided would have raised a SyntaxError, so omitting the 'def's can't
be the cause of the actual problem reported.
--
http://mail.python.org/mailman/listinfo/python-list
Re: bad certificate error
jakecjacobson wrote:
Hi,
I am getting the following error when doing a post to REST API,
Enter PEM pass phrase:
Traceback (most recent call last):
File ./ices_catalog_feeder.py, line 193, in ?
main(sys.argv[1])
File ./ices_catalog_feeder.py, line 60, in main
post2Catalog(catalog_host, catalog_port, catalog_path, os.path.join
(input_dir, file), collection_name, key_file, cert_file)
File ./ices_catalog_feeder.py, line 125, in post2Catalog
connection.request('POST', path, parameters, head)
File /usr/lib/python2.4/httplib.py, line 810, in request
self._send_request(method, url, body, headers)
File /usr/lib/python2.4/httplib.py, line 833, in _send_request
self.endheaders()
File /usr/lib/python2.4/httplib.py, line 804, in endheaders
self._send_output()
File /usr/lib/python2.4/httplib.py, line 685, in _send_output
self.send(msg)
File /usr/lib/python2.4/httplib.py, line 652, in send
self.connect()
File /usr/lib/python2.4/httplib.py, line 1079, in connect
ssl = socket.ssl(sock, self.key_file, self.cert_file)
File /usr/lib/python2.4/socket.py, line 74, in ssl
return _realssl(sock, keyfile, certfile)
socket.sslerror: (1, 'error:14094412:SSL
routines:SSL3_READ_BYTES:sslv3 alert bad certificate')
What SSL implementation are you using? The old one from Python 2.4
doesn't even check the certificate chain. M2Crypto does, and the new
SSL module does, but in each case you have to provide a root certificate
file. (The one from Mozilla is available.)
John Nagle
--
http://mail.python.org/mailman/listinfo/python-list
Re: SEC forms parsing
mpython wrote: I am looking for any python examples that have written to parse SEC filings (Security Exchange Commission's EDGAR system),or just a pointer to best modules to use. I've been doing that in Perl for years. See www.downside.com. Actually extracting financial statements is possible, but you run into a patent problem with a Price-Waterhouse patent if you try to do a good job. What are you trying to do? John Nagle -- http://mail.python.org/mailman/listinfo/python-list
Re: Help with sql and python
catalinf...@gmail.com catalinf...@gmail.com (cc) wrote: cc Hello ! cc I have accont on myphpadmin on my server. cc I want to create one script in python. cc This script manage sql task from my sql server . cc How i make this in a simple way ? See http://mysql-python.sourceforge.net/MySQLdb.html This really has nothing to do with myphpadmin (you probably mean phpMyAdmin but even then it has nothing to do with it except that both acess a MySQL database). And if you give yourself a name than we might have an idea if we are talking to a human being or a robot. -- Piet van Oostrum p...@cs.uu.nl URL: http://pietvanoostrum.com [PGP 8DAE142BE17999C4] Private email: p...@vanoostrum.org -- http://mail.python.org/mailman/listinfo/python-list
Re: New implementation of re module
On Jul 29, 10:45 am, MRAB pyt...@mrabarnett.plus.com wrote:
Mike wrote:
- findall/finditer doesn't find overlapping matches. Sometimes you
really *do* want to know all possible matches, even if they overlap.
Perhaps by adding overlapped=True?
Something like that would be great, yes.
- split won't split on empty patterns, e.g. empty lookahead patterns.
Already addressed (see issue2636 for the full details).
Glad to hear it.
- Repeated subgroup match information is not available. That is, for
a match like this
re.match('(.){3}', 'xyz')
there's no way to discover that the subgroup first matched 'x', then
matched 'y', and finally matched 'z'. Here is one past proposal
(mine), perhaps over-complex, to address this problem:
http://mail.python.org/pipermail/python-dev/2004-August/047238.html
Yikes! I think I'll let you code that... :-)
I agree that that document looks a little scary--maybe I was trying to
bite off too much at once.
My intuition, though, is that the basic idea should be fairly simple
to implement, at least for a depth-first matcher. The repeated match
subgroups are already being discovered, it's just that they're not
being saved, so there's no way to report them out once a complete
match is found. If some trail of breadcrumbs were pushed onto a stack
during the DFS, it could be traced at the end. And the whole thing
might not even been that expensive to do.
The hardest parts about this, in my mind, are figuring out how to
report the repeated matches out in a useful form (hence all that
detail in the proposal), and getting users to understand that using
this feature *could* suck up a lot of memory, if they're not careful.
As always, it's possible that my intuition is totally wrong. Plus I'm
not sure how this would work out in the breadth-first case.
Details aside, I would really, really, really like to have a way to
get at the repeated subgroup matches. I write a lot of code that
would be one-liners if this capability existed. Plus, it just plain
burns me that Python is discovering this information but impudently
refuses to tell me what it's found! ;-)
--
http://mail.python.org/mailman/listinfo/python-list
Re: open a file in python
jayshree jayshree06c...@gmail.com (j) wrote:
The Exact Problem is how to use the key containing by .pem file for
'encryption' . can i print the contents of the .pem file
I have already answered this question in a previous thread. It is not
very helpful if you repeat asking the same or similar questions in
different threads, especially if you don't take notice of the answers
given. I will repeat it once here:
load_pub_key requires a file name, not the contents of the file.
So use rsa = M2Crypto.RSA.load_pub_key('my_key.public.pem') and leave
the open line out.
--
Piet van Oostrum p...@cs.uu.nl
URL: http://pietvanoostrum.com [PGP 8DAE142BE17999C4]
Private email: p...@vanoostrum.org
--
http://mail.python.org/mailman/listinfo/python-list
Does underscore has any special built-in meaningin Python ?
Hello everybody, I have just started learning Python.I heard its simple so I pick a presentation [1] and tried to work on it.But when it comes to underscores leading and trailing an object I dont understand any.I look through the python manual also but that was not helping .I searched some forums and I still dont have a clear picture. What is the functionality of __ or _ , leading or trailing an object , class ot function ? Is it just a naming convention to note special functions and objects , or it really mean someting to Python ? Thanks ahead , [1] http://www.aleax.it/goo_py4prog.pdf -- http://mail.python.org/mailman/listinfo/python-list
Re: Print value CLOB via cx_Oracle
On 28 Lip, 20:02, Vincent Vega lemm...@gmail.com wrote: Hi, I call function in Oracle database use cx_Oracle. In standard I define: db = cx_Oracle.connect(username, password, tnsentry) cursor = db.cursor() I create variable 'y' (result function 'fun_name') and call function 'fun_name': y = cursor.var(cx_Oracle.CLOB) cursor.callfunc(fun_name, cx_Oracle.CLOB, y) When I print variable 'y' I receive: cx_Oracle.CLOB with value cx_Oracle.LOB object at 0x0099 How can I get value variable 'y'??? How read cx_Oracle.LOB object at 0x0099??? Vincent Vega Note: Off course y.read() does not work, cause 'y'is CLOB not LOB. (see datatypes table in site:http://www.oracle.com/technology/pub/articles/prez-python-queries.html) The solution is simple: print y.getvalue() (see: http://cx-oracle.sourceforge.net/html/variable.html) Thanks! :) Vincent Vega -- http://mail.python.org/mailman/listinfo/python-list
Re: Run pyc file without specifying python path ?
Barak, Ron wrote: Hi, I wanted to make a python byte-code file executable, expecting to be able to run it without specifying python on the (Linux bash) command line. So, I wrote the following: [r...@vmlinux1 python]# cat test_pyc.py #!/usr/bin/env python print hello [r...@vmlinux1 python]# and made its pyc file executable: [r...@vmlinux1 python]# ls -ls test_pyc.pyc 4 -rwxr-xr-x 1 root root 106 Jul 29 14:22 test_pyc.pyc [r...@vmlinux1 python]# So, I see: [r...@vmlinux1 python]# file test_pyc.py* test_pyc.py: a python script text executable test_pyc.pyc: python 2.3 byte-compiled [r...@vmlinux1 python]# If I try to do the following, no problem: [r...@vmlinux1 python]# python test_pyc.pyc hello [r...@vmlinux1 python]# However, the following fails: [r...@vmlinux1 python]# ./test_pyc.pyc -bash: ./test_pyc.pyc: cannot execute binary file [r...@vmlinux1 python]# Is there a way to run a pyc file without specifying the python path ? Bye, Ron. I don't currently run Unix, but I think I know the problem. In a text file, the shell examines the first line, and if it begins #! it's assumed to point to the executable of an interpreter for that text file. Presumably the same trick doesn't work for a .pyc file. Why not write a trivial wrapper.py file, don't compile it, and let that invoke the main code in the .pyc file? Then make wrapper.py executable, and you're ready to go. DaveA -- http://mail.python.org/mailman/listinfo/python-list
Re: Does underscore has any special built-in meaningin Python ?
On Wed, Jul 29, 2009 at 1:59 PM, dandi kain dandi.k...@gmail.com wrote: Hello everybody, I have just started learning Python.I heard its simple so I pick a presentation [1] and tried to work on it.But when it comes to underscores leading and trailing an object I dont understand any.I look through the python manual also but that was not helping .I searched some forums and I still dont have a clear picture. What is the functionality of __ or _ , leading or trailing an object , class ot function ? Is it just a naming convention to note special functions and objects , or it really mean someting to Python ? It's just a convention for the most part. A single leading underscore is used for private attributes. Two leading underscores will affect the code- it mangles the variable name so that you don't have to worry about the value being overwritten by a subclass. For instance class Foo(object) : def __init__(self) : self.__bar = '' foo = Foo() will store the attribute as foo._Foo__bar. Also, the magic methods- the ones that are used for operations and built-in stuff, all have two leading and two trailing underscores. These are things like __add__ (+), __eq__ (=), __cmp__ (old way for comparisons), __len__ (len), __str__ (str), and so on. Thanks ahead , [1] http://www.aleax.it/goo_py4prog.pdf -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: Help with sql and python
catalinf...@gmail.com wrote: Hello ! I have accont on myphpadmin on my server. I want to create one script in python. This script manage sql task from my sql server . How i make this in a simple way ? Thank you ! It's seldom simple. I'm guessing it's not your server, but is actually a webserver, located remotely, and to which you have only ftp access. Next questions are do you have access to the admins of the machine, what kind of machine is it, what OS is it running, does it have Python installed, what version(s)? Next questions are dependent on the answers to those questions. For example, on Unix systems you'll generally need to be able to chmod the file. But before you ask your admins those questions, you need to ask how you *want* to run the script. Creating it isn't enough, if you don't run it. You might be running it over the web, via URL, perhaps using CGI. You might be activating it via some remote console, or rsh. Or it might be a cron job. It might need various privileges to do what you expect. And if it's going to run continuously, or if it uses lots of resources, the admins may refuse it entirely. DaveA -- http://mail.python.org/mailman/listinfo/python-list
Re: simple splash screen?
NighterNet wrote: I am trying to make a simple splash screen from python 3.1.Not sure where to start looking for it. Can any one help? Sure, almost the same as with Python 2 :-) But to be a bit more specific: Only works if you got Python 3 installed with tkinter import tkinter IMAGE_PATH = /path/to/image class Splash(object): Splash Screen GUI def __init__(self, root): self.root = root # No window borders and decoration self.root.overrideredirect(True) # Get the size of the screen screen_width = self.root.winfo_screenwidth() screen_height = self.root.winfo_screenheight() # Full screen geometry_text = %dx%d+0+0 % (screen_width, screen_height) self.root.geometry(geometry_text) # Display an image self.label = tkinter.Label(self.root) # Only GIF and PGM/PPM supported, for more information see: self.label._image = tkinter.PhotoImage(file=IMAGE_PATH) # http://effbot.org/tkinterbook/photoimage.htm self.label.configure(image = self.label._image) self.label.pack() # This will quit the screen after about 5 seconds self.root.after(5000, self.root.quit) if __name__ == '__main__': ROOT = tkinter.Tk() APPL = Splash(ROOT) ROOT.mainloop() -- MPH http://blog.dcuktec.com 'If consumed, best digested with added seasoning to own preference.' -- http://mail.python.org/mailman/listinfo/python-list
Re: instead of depending on data = array('h') .. write samples 1 by 1 to w = wave.open(wav.wav, w)
o wow .. there's still a lot to learn ..
okay .. if i get stucked with the memory usage issue
will try this hybrid .. thanx for the example!!
it took about 40 min to render 1min of wav
so i'll just keep this project like 15 sec oriented
and maybe that'll keep me away from the mem trouble
and my oil.py is still so cheap..
sad thing is that the result sound strange is true to
all versions :s
thanx again anyway!
On Wed, Jul 29, 2009 at 5:21 PM, Peter Otten__pete...@web.de wrote:
'2+ wrote:
it says
Wave_write.writeframes(data)
will that mean
from array import array
is a must?
this does the job:
import oil
import wave
from array import array
a = oil.Sa()
w = wave.open(current.wav, w)
w.setnchannels(2)
w.setsampwidth(2)
w.setframerate(44100)
data = array('h')
for gas in range(44100 * 5):
a.breath()
r = int(32767 * (a.pulse(1) + a.pulse(2) + a.pulse(3)) / 3.0)
l = int(32767 * (a.pulse(4) + a.pulse(5) + a.pulse(6)) / 3.0)
data.append(r)
data.append(l)
w.writeframes(data.tostring())
w.close()
don't like array becoming so huge so tested this and it was also okay:
for gas in range(44100 * 5):
a.breath()
data = array('h')
r = int(32767 * (a.pulse(1) + a.pulse(2) + a.pulse(3)) / 3.0)
l = int(32767 * (a.pulse(4) + a.pulse(5) + a.pulse(6)) / 3.0)
data.append(r)
data.append(l)
w.writeframes(data.tostring())
but without array .. it becomes 15secs(3 times longer than was
intended to be) of wav file:
for gas in range(44100 * 5):
a.breath()
r = int(32767 * (a.pulse(1) + a.pulse(2) + a.pulse(3)) / 3.0)
l = int(32767 * (a.pulse(4) + a.pulse(5) + a.pulse(6)) / 3.0)
w.writeframes(hex(r))
w.writeframes(hex(l))
Doesn't it sound strange, too? You are writing bogus bytes to the file.
Compare:
import array
array.array(h, [42]).tostring()
'*\x00'
hex(42)
'0x2a'
Not only do they differ in length, the contents are different, too. If
you're unfamiliar with string escape codes, here's a way to see the bytes:
map(ord, array.array(h, [42]).tostring())
[42, 0]
map(ord, hex(42))
[48, 120, 50, 97]
should i just be happy with depennding on using array?
or is there a solution to make the last one work properly?
There is a way to make the last one work: use struct.pack(h, r) instead of
hex(r). I'm of course assuming that the first version does give you the
desired result. You should not continue before you have verified that.
I still recommend array for performance reasons. If memory usage is an issue
you can adopt a hybrid approach:
# untested
from itertools import islice
from array import array
def gen_data():
for gas in xrange(44100 * 5): # range -- xrange
a.breath()
r = int(32767 * (a.pulse(1) + a.pulse(2) + a.pulse(3)) / 3.0)
l = int(32767 * (a.pulse(4) + a.pulse(5) + a.pulse(6)) / 3.0)
yield r
yield l
data = gen_data()
N = 2**20
while True:
chunk = array('h')
chunk.extend(islice(data, N))
if not chunk:
break
w.writeframes(chunk.tostring())
This will limit the array size to 4N bytes.
Peter
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Re: escaping characters in filenames
J Kenneth King wrote: I wrote a script to process some files using another program. One thing I noticed was that both os.listdir() and os.path.walk() will return unescaped file names (ie: My File With Spaces Stuff instead of My\ File\ With\ Spaces\ \\ Stuff). I haven't had much success finding a module or recipe that escapes file names and was wondering if anyone could point me in the right direction. As an aside, the script is using subprocess.call() with the shell=True parameter. There isn't really a reason for doing it this way (was just the fastest way to write it and get a prototype working). I was wondering if Popen objects were sensitive to unescaped names like the shell. I intend to refactor the function to use Popen objects at some point and thought perhaps escaping file names may not be entirely necessary. Cheers There are dozens of meanings for escaping characters in strings. Without some context, we're wasting our time. For example, if the filename is to be interpreted as part of a URL, then spaces are escaped by using %20. Exactly who is going to be using this string you think you have to modify? I don't know of any environment which expects spaces to be escaped with backslashes. Be very specific. For example, if a Windows application is parsing its own command line, you need to know what that particular application is expecting -- Windows passes the entire command line as a single string. But of course you may be invoking that application using subprocess.Popen(), in which case some transformations happen to your arguments before the single string is built. Then some more transformations may happen in the shell. Then some more in the C runtime library of the new process (if it happens to be in C, and if it happens to use those libraries). I'm probably not the one with the answer. But until you narrow down your case, you probably won't attract the attention of whichever person has the particular combination of experience that you're hoping for. DaveA -- http://mail.python.org/mailman/listinfo/python-list
Re: Semaphore Techniques
I'm working with up to 3 process session per server, each process running three threads. I was wishing to tie back the 3 session/server to a semaphore, but everything (and everyone) say semaphores are only good per process. -- http://mail.python.org/mailman/listinfo/python-list
Re: Semaphore Techniques
That was my original idea. Restricting each process by pid: #bash procs=`ps aux | grep script.pl | grep -v grep | wc -l` if [ $procs -lt 3 ]; then python2.4 script.py config.xml else exit 0 fi -- http://mail.python.org/mailman/listinfo/python-list
Re: Semaphore Techniques
John D Giotta schrieb: I'm working with up to 3 process session per server, each process running three threads. I was wishing to tie back the 3 session/server to a semaphore, but everything (and everyone) say semaphores are only good per process. That's not true. Named semaphores are the best solution for your problem and I said so yesterday. Christian -- http://mail.python.org/mailman/listinfo/python-list
Re: Very Strange Problem
Omer Khalid wrote:
Hi,
I am having a very strange problem with modifying a variable in a list in my
program. Here is the code:
# a list that contains dictionary objects
jobs = []
index=5
for each in range(index):
jobs.append({'v':0})
some_function(index):
if jobs[index]['v'] == 0:
# set it to 1
jobs[index]['v'] = 1
print Set to 1
else:
print Already set to 1
loop():
index=0
for each in range(len(jobs)):
some_function(index)
index +=1
Apparently, the jobs[index]['v'] never get updated in the some_function but
the print statement afterwards get printed...
What's really surprising is that there are no errors or exceptions and my my
program runs in a single thread...so i have been unable to explain this
behavior.
Any insight would be much appreciated!
Cheers
Omer
There are four things to fix before the program does anything much at
all. Two places you're missing the def, indentation is inconsistent,
and you never actually call either of the functions. The first three
are syntax errors, so presumably your cut/paste in your computer is broken.
Once I make those four corrections, I get the following output:
Set to 1
Set to 1
Set to 1
Set to 1
Set to 1
But you never said what you got, nor what you expected. That's
certainly what I'd expect. And if you make a second call to loop() in
your outer code, you get five copies of Already set to 1
BTW, there are a number of things that could be done better. The main
one I'll point out is that you shouldn't re-use a global variable
'index' as a local with different meaning. As someone else pointed out,
since the global is a constant, making it all uppercase is the convention.
DaveA
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Re: escaping characters in filenames
On Wed, 29 Jul 2009 09:29:55 -0400, J Kenneth King wrote: I wrote a script to process some files using another program. One thing I noticed was that both os.listdir() and os.path.walk() will return unescaped file names (ie: My File With Spaces Stuff instead of My\ File\ With\ Spaces\ \\ Stuff). I haven't had much success finding a module or recipe that escapes file names and was wondering if anyone could point me in the right direction. As an aside, the script is using subprocess.call() with the shell=True parameter. There isn't really a reason for doing it this way (was just the fastest way to write it and get a prototype working). I was wondering if Popen objects were sensitive to unescaped names like the shell. I intend to refactor the function to use Popen objects at some point and thought perhaps escaping file names may not be entirely necessary. Note that subprocess.call() is nothing more than: def call(*popenargs, **kwargs): return Popen(*popenargs, **kwargs).wait() plus a docstring. It accepts exactly the same arguments as Popen(), with the same semantics. If you want to run a command given a program and arguments, you should pass the command and arguments as a list, rather than trying to construct a string. On Windows the value of shell= is unrelated to whether the command is a list or a string; a list is always converted to string using the list2cmdline() function. Using shell=True simply prepends cmd.exe /c to the string (this allows you to omit the .exe/.bat/etc extension for extensions which are in %PATHEXT%). On Unix, a string is first converted to a single-element list, so if you use a string with shell=False, it will be treated as the name of an executable to be run without arguments, even if contains spaces, shell metacharacters etc. The most portable approach seems to be to always pass the command as a list, and to set shell=True on Windows and shell=False on Unix. The only reason to pass a command as a string is if you're getting a string from the user and you want it to be interpreted using the platform's standard shell (i.e. cmd.exe or /bin/sh). If you want it to be interpreted the same way regardless of platform, parse it into a list using shlex.split(). -- http://mail.python.org/mailman/listinfo/python-list
set variable to looping index?
Hi,
I am trying to set the return value from a function to a name which I
grab from the for loop. I can't work out how I can do this without
using an if statement...
for f in var1_fn, var2_fn, var3_fn:
if f.split('.')[0] == 'var1':
var1 = call_some_function(f)
.
.
.
etc
Really I would like to remove the need for this if loop and I am sure
there is a simple way I am missing?
Many thanks
Martin
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Re: 64-bit issues with dictionaries in Python 2.6
Are there any known issues with dictionaries in Python 2.6 (not 2.6.2) when running on a 64-bit platform? No, none. Regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
Re: Very Strange Problem
Hi Dave,
Thanks for your reply. I actually didn't cut and paste my code as it was
dispersed in different places, i typed the logic behind my code in the email
(and obiviously made some typos, indentations is some thing else) but my
real code does not have these problems as my application runs fine with out
errors...
Except that the line where i want to update the value doesn't get updated
and no exception is thrown. What's surprising for me is that i am doing the
same thing in hundreds of places in my 3k+ line code but by some reason this
part doesn't work...
As far as the global variables are concerned, i am using them in other
places too and didn't see any problems.
I think some thing else is going on here as the statement above and below my
modified lines get executed.
Is there a way in Python to debug memory address or to see where in memory
this object is stored, and is there a lock on it or else?
Thanks,
Omer
**
On Wed, Jul 29, 2009 at 8:56 PM, Dave Angel da...@ieee.org wrote:
Omer Khalid wrote:
Hi,
I am having a very strange problem with modifying a variable in a list in
my
program. Here is the code:
# a list that contains dictionary objects
jobs = []
index=5
for each in range(index):
jobs.append({'v':0})
some_function(index):
if jobs[index]['v'] == 0:
# set it to 1
jobs[index]['v'] = 1
print Set to 1
else:
print Already set to 1
loop():
index=0
for each in range(len(jobs)):
some_function(index)
index +=1
Apparently, the jobs[index]['v'] never get updated in the some_function
but
the print statement afterwards get printed...
What's really surprising is that there are no errors or exceptions and my
my
program runs in a single thread...so i have been unable to explain this
behavior.
Any insight would be much appreciated!
Cheers
Omer
There are four things to fix before the program does anything much at all.
Two places you're missing the def, indentation is inconsistent, and you
never actually call either of the functions. The first three are syntax
errors, so presumably your cut/paste in your computer is broken.
Once I make those four corrections, I get the following output:
Set to 1
Set to 1
Set to 1
Set to 1
Set to 1
But you never said what you got, nor what you expected. That's certainly
what I'd expect. And if you make a second call to loop() in your outer
code, you get five copies of Already set to 1
BTW, there are a number of things that could be done better. The main one
I'll point out is that you shouldn't re-use a global variable 'index' as a
local with different meaning. As someone else pointed out, since the global
is a constant, making it all uppercase is the convention.
DaveA
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Re: simple splash screen?
On Jul 29, 11:16 am, Martin P. Hellwig martin.hell...@dcuktec.org wrote: NighterNet wrote: I am trying to make a simple splash screen from python 3.1.Not sure where to start looking for it. Can any one help? Sure, almost the same as with Python 2 :-) But to be a bit more specific: Only works if you got Python 3 installed with tkinter import tkinter IMAGE_PATH = /path/to/image class Splash(object): Splash Screen GUI def __init__(self, root): self.root = root # No window borders and decoration self.root.overrideredirect(True) # Get the size of the screen screen_width = self.root.winfo_screenwidth() screen_height = self.root.winfo_screenheight() # Full screen geometry_text = %dx%d+0+0 % (screen_width, screen_height) self.root.geometry(geometry_text) # Display an image self.label = tkinter.Label(self.root) # Only GIF and PGM/PPM supported, for more information see: self.label._image = tkinter.PhotoImage(file=IMAGE_PATH) #http://effbot.org/tkinterbook/photoimage.htm self.label.configure(image = self.label._image) self.label.pack() # This will quit the screen after about 5 seconds self.root.after(5000, self.root.quit) if __name__ == '__main__': ROOT = tkinter.Tk() APPL = Splash(ROOT) ROOT.mainloop() -- MPHhttp://blog.dcuktec.com 'If consumed, best digested with added seasoning to own preference.' Thanks it help. Sorry about that, I was just wander what kind of answer and if there are other methods to learn it. Is there a way to position image to the center screen? -- http://mail.python.org/mailman/listinfo/python-list
Re: Very Strange Problem
Omer Khalid wrote: Hi, I am having a very strange problem with modifying a variable in a list in my program. Here is the code: To me, this sentence clearly implies that the code that follows is the code that had the problem. Since the posted code cannot run, it clearly is not. People should test code to be posted before posting unless they clearly label it as 'untested'. Original posters, of course, should run the code first. tjr -- http://mail.python.org/mailman/listinfo/python-list
Re: Very Strange Problem
Omer Khalid wrote:
Hi Dave,
Thanks for your reply. I actually didn't cut and paste my code as it was
dispersed in different places, i typed the logic behind my code in the email
(and obiviously made some typos, indentations is some thing else) but my
real code does not have these problems as my application runs fine with out
errors...
Except that the line where i want to update the value doesn't get updated
and no exception is thrown. What's surprising for me is that i am doing the
same thing in hundreds of places in my 3k+ line code but by some reason this
part doesn't work...
As far as the global variables are concerned, i am using them in other
places too and didn't see any problems.
I think some thing else is going on here as the statement above and below my
modified lines get executed.
Is there a way in Python to debug memory address or to see where in memory
this object is stored, and is there a lock on it or else?
Thanks,
Omer
**
On Wed, Jul 29, 2009 at 8:56 PM, Dave Angel da...@ieee.org wrote:
Omer Khalid wrote:
Hi,
I am having a very strange problem with modifying a variable in a list in
my
program. Here is the code:
# a list that contains dictionary objects
jobs = []
index=5
for each in range(index):
jobs.append({'v':0})
some_function(index):
if jobs[index]['v'] == 0:
# set it to 1
jobs[index]['v'] = 1
print Set to 1
else:
print Already set to 1
loop():
index=0
for each in range(len(jobs)):
some_function(index)
index +=1
Apparently, the jobs[index]['v'] never get updated in the some_function
but
the print statement afterwards get printed...
What's really surprising is that there are no errors or exceptions and my
my
program runs in a single thread...so i have been unable to explain this
behavior.
Any insight would be much appreciated!
Cheers
Omer
There are four things to fix before the program does anything much at all.
Two places you're missing the def, indentation is inconsistent, and you
never actually call either of the functions. The first three are syntax
errors, so presumably your cut/paste in your computer is broken.
Once I make those four corrections, I get the following output:
Set to 1
Set to 1
Set to 1
Set to 1
Set to 1
But you never said what you got, nor what you expected. That's certainly
what I'd expect. And if you make a second call to loop() in your outer
code, you get five copies of Already set to 1
BTW, there are a number of things that could be done better. The main one
I'll point out is that you shouldn't re-use a global variable 'index' as a
local with different meaning. As someone else pointed out, since the global
is a constant, making it all uppercase is the convention.
DaveA
(You top-posted, so your ,message is out of sequence. More and more
people are doing that in this list.)
...Except that the line where i want to update the value doesn't
get updated...
And what makes you think that? You never answered my question. What did you
expect for output, and what did you get? I got exactly what I expected, when I
ran it.
... Is there a way in Python to debug memory address or
to see where in memory this object is stored, and
is there a lock on it or else?
If there really were a bug in the language, you might need such a tool.
I use Komodo IDE as a debugger, but there was no need in this case.
Adding a few print statements might clear up your confusion, but since
you haven't spelled out what it is, I can't suggest where. How about if
you just add aprint jobsat the beginning of some_function() ?
Then you could see things getting updated perfectly.
DaveA
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Re: Does underscore has any special built-in meaningin Python ?
29-07-2009 Benjamin Kaplan benjamin.kap...@case.edu wrote: On Wed, Jul 29, 2009 at 1:59 PM, dandi kain dandi.k...@gmail.com wrote: [snip What is the functionality of __ or _ , leading or trailing an object , class ot function ? Is it just a naming convention to note special functions and objects , or it really mean someting to Python ? It's just a convention for the most part. A single leading underscore is used for private attributes. Two leading underscores will affect the code- Single leading underscore in some situations also affect the code... See: * http://docs.python.org/reference/lexical_analysis.html#reserved-classes-of-identifiers * http://docs.python.org/reference/datamodel.html#object.__del__ (in the the red Warning frame) -- Jan Kaliszewski (zuo) z...@chopin.edu.pl -- http://mail.python.org/mailman/listinfo/python-list
Re: Does underscore has any special built-in meaningin Python ?
Benjamin Kaplan wrote: On Wed, Jul 29, 2009 at 1:59 PM, dandi kain dandi.k...@gmail.com wrote: Hello everybody, I have just started learning Python.I heard its simple so I pick a presentation [1] and tried to work on it.But when it comes to underscores leading and trailing an object I dont understand any.I look through the python manual also but that was not helping .I searched some forums and I still dont have a clear picture. What is the functionality of __ or _ , leading or trailing an object , class ot function ? Is it just a naming convention to note special functions and objects , or it really mean someting to Python ? It's just a convention for the most part. A single leading underscore is used for private attributes. Two leading underscores will affect the code- it mangles the variable name so that you don't have to worry about the value being overwritten by a subclass. For instance class Foo(object) : def __init__(self) : self.__bar = '' foo = Foo() will store the attribute as foo._Foo__bar. Also, the magic methods- the ones that are used for operations and built-in stuff, all have two leading and two trailing underscores. These are things like __add__ (+), __eq__ (=), __cmp__ (old way for comparisons), __len__ (len), __str__ (str), and so on. For this last, see http://docs.python.org/dev/py3k/reference/datamodel.html#special-method-names -- http://mail.python.org/mailman/listinfo/python-list
How to gunzip-iterate over a file?
I need to iterate over the lines of *very* large (1 GB) gzipped files. I would like to do this without having to read the full compressed contents into memory so that I can apply zlib.decompress to these contents. I also would like to avoid having to gunzip the file (i.e. creating an uncompressed version of the file in the filesystem) prior to iterating over it. Basically I'm looking for something that will give me the same functionality as Perl's gzip IO layer, which looks like this (from the documentation): use PerlIO::gzip; open FOO, :gzip, file.gz or die $!; print while FOO; # And it will be uncompressed... What's the best way to achieve the same functionality in Python? TIA! kynn -- http://mail.python.org/mailman/listinfo/python-list
Re: How to gunzip-iterate over a file?
On 2009-07-29 15:05, kj wrote:
I need to iterate over the lines of *very* large (1 GB) gzipped
files. I would like to do this without having to read the full
compressed contents into memory so that I can apply zlib.decompress
to these contents. I also would like to avoid having to gunzip
the file (i.e. creating an uncompressed version of the file in the
filesystem) prior to iterating over it.
Basically I'm looking for something that will give me the same
functionality as Perl's gzip IO layer, which looks like this (from
the documentation):
use PerlIO::gzip;
open FOO, :gzip, file.gz or die $!;
print whileFOO; # And it will be uncompressed...
What's the best way to achieve the same functionality in Python?
http://docs.python.org/library/gzip
import gzip
f = gzip.open('filename.gz')
for line in f:
print line
f.close()
--
Robert Kern
I have come to believe that the whole world is an enigma, a harmless enigma
that is made terrible by our own mad attempt to interpret it as though it had
an underlying truth.
-- Umberto Eco
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Differences Between Arrays and Matrices in Numpy
What are some differences between arrays and matrices using the Numpy library? When would I want to use arrays instead of matrices and vice versa? -- http://mail.python.org/mailman/listinfo/python-list
Does python have the capability for driver development ?
hello there, I've a question : I want to know does python have any capability for using Ring0 and kernel functions for driver and device development stuff . if there's such a feature it is very good, and if there something for this kind that you know please refer me to some reference and show me some snippet . thanks - Malc0de -- http://mail.python.org/mailman/listinfo/python-list
delayed sys.exit?
In the attached http://www.nabble.com/file/p24726902/test.py test.py code, it appears that additional statements execute after the call to sys.exit(0). I'll be grateful if anyone can shed light on why this is happening. Below is a copy of some sample I/O. Note that in the last case I get additional output after what should be the final error message. In [126]: run test Input a string: 1,2 [1, 2] In [127]: run test Input a string: 1-3 [1, 2, 3] In [128]: run test Input a string: 1,4,5-12 [1, 4, 5, 6, 7, 8, 9, 10, 11, 12] In [129]: run test Input a string: 0 ERROR: 0 is invalid; run numbers must be positive. ERROR: '0' is not a valid run number. -- View this message in context: http://www.nabble.com/delayed-sys.exit--tp24726902p24726902.html Sent from the Python - python-list mailing list archive at Nabble.com. -- http://mail.python.org/mailman/listinfo/python-list
Re: escaping characters in filenames
Nobody nob...@nowhere.com writes: On Wed, 29 Jul 2009 09:29:55 -0400, J Kenneth King wrote: I wrote a script to process some files using another program. One thing I noticed was that both os.listdir() and os.path.walk() will return unescaped file names (ie: My File With Spaces Stuff instead of My\ File\ With\ Spaces\ \\ Stuff). I haven't had much success finding a module or recipe that escapes file names and was wondering if anyone could point me in the right direction. As an aside, the script is using subprocess.call() with the shell=True parameter. There isn't really a reason for doing it this way (was just the fastest way to write it and get a prototype working). I was wondering if Popen objects were sensitive to unescaped names like the shell. I intend to refactor the function to use Popen objects at some point and thought perhaps escaping file names may not be entirely necessary. Note that subprocess.call() is nothing more than: def call(*popenargs, **kwargs): return Popen(*popenargs, **kwargs).wait() plus a docstring. It accepts exactly the same arguments as Popen(), with the same semantics. If you want to run a command given a program and arguments, you should pass the command and arguments as a list, rather than trying to construct a string. On Windows the value of shell= is unrelated to whether the command is a list or a string; a list is always converted to string using the list2cmdline() function. Using shell=True simply prepends cmd.exe /c to the string (this allows you to omit the .exe/.bat/etc extension for extensions which are in %PATHEXT%). On Unix, a string is first converted to a single-element list, so if you use a string with shell=False, it will be treated as the name of an executable to be run without arguments, even if contains spaces, shell metacharacters etc. The most portable approach seems to be to always pass the command as a list, and to set shell=True on Windows and shell=False on Unix. The only reason to pass a command as a string is if you're getting a string from the user and you want it to be interpreted using the platform's standard shell (i.e. cmd.exe or /bin/sh). If you want it to be interpreted the same way regardless of platform, parse it into a list using shlex.split(). I understand; I think I was headed towards subprocess.Popen() either way. It seems to handle the problem I posted about. And I got to learn a little something on the way. Thanks! Only now there's a new problem in that the output of the program is different if I run it from Popen than if I run it from the command line. The program in question is 'pdftotext'. More investigation to ensue. Thanks again for the helpful post. -- http://mail.python.org/mailman/listinfo/python-list
Re: Differences Between Arrays and Matrices in Numpy
On 2009-07-29 15:23, Nanime Puloski wrote: What are some differences between arrays and matrices using the Numpy library? When would I want to use arrays instead of matrices and vice versa? You will want to ask numpy questions on the numpy mailing list: http://www.scipy.org/Mailing_Lists An overview of how the matrix subclass differs from ndarray, see the documentation: http://docs.scipy.org/doc/numpy/reference/arrays.classes.html#matrix-objects Basically, I suggest that you just use regular arrays always. There is a syntactical convenience to matrix objects, but it does cause incompatibilities with the majority of code that is written for regular arrays. The convenience is usually not worth the cost. -- Robert Kern I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth. -- Umberto Eco -- http://mail.python.org/mailman/listinfo/python-list
Re: delayed sys.exit?
In the attached http://www.nabble.com/file/p24726902/test.py test.py code, it appears that additional statements execute after the call to sys.exit(0). I'll be grateful if anyone can shed light on why this is happening. Below is a copy of some sample I/O. Note that in the last case I get additional output after what should be the final error message. A bare except: catches ALL exceptions; including SystemExit which is generated by sys.exit. And KeyboardInterrupt, too. That's why its basically a bad idea to use bare excepts unless you really, really, really need to. Try 'except Exception' instead. SystemExit and such do not inherit from Exception. --S -- http://mail.python.org/mailman/listinfo/python-list
Re: delayed sys.exit?
Dr. Phillip M. Feldman wrote: In the attached http://www.nabble.com/file/p24726902/test.py test.py code, it appears that additional statements execute after the call to sys.exit(0). I'll be grateful if anyone can shed light on why this is happening. Below is a copy of some sample I/O. Note that in the last case I get additional output after what should be the final error message. In [126]: run test Input a string: 1,2 [1, 2] In [127]: run test Input a string: 1-3 [1, 2, 3] In [128]: run test Input a string: 1,4,5-12 [1, 4, 5, 6, 7, 8, 9, 10, 11, 12] In [129]: run test Input a string: 0 ERROR: 0 is invalid; run numbers must be positive. ERROR: '0' is not a valid run number. sys.exit raises an SystemExit exception, which then gets caught by the bare 'except' of the enclosing try...except... statement. A lot of things can raise an exception, which is why bare 'except's are a bad idea; catch only those you expect. -- http://mail.python.org/mailman/listinfo/python-list
Re: delayed sys.exit?
Dr. Phillip M. Feldman wrote: In the attached http://www.nabble.com/file/p24726902/test.py test.py code, it appears that additional statements execute after the call to sys.exit(0). try: # If the conversion to int fails, nothing is appended to the list: Runs.append(int(strs[i])) if Runs[-1] = 0: print 'ERROR: ' + str(Runs[-i]) + \ ' is invalid; run numbers must be positive.' sys.exit(0) except: sys.exit() works by raising a SystemExit exception which is caught by the bare except. http://docs.python.org/library/sys.html#sys.exit http://docs.python.org/library/exceptions.html#exceptions.SystemExit As a general rule try to be as specific as possible when catching exceptions. Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: set variable to looping index?
Martin wrote:
I am trying to set the return value from a function to a name which I
grab from the for loop. I can't work out how I can do this without
using an if statement...
for f in var1_fn, var2_fn, var3_fn:
if f.split('.')[0] == 'var1':
var1 = call_some_function(f)
.
.
.
etc
Really I would like to remove the need for this if loop and I am sure
there is a simple way I am missing?
Use dictionaries:
functions = {var1: some_function, var2: some_other_function, ...}
return_values = {}
for arg in var1_fn, var2_fn, var3_fn:
key = arg.split(.)[0]
return_values[key] = functions[key](arg)
Peter
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Re: Does python have the capability for driver development ?
MalC0de schrieb: hello there, I've a question : I want to know does python have any capability for using Ring0 and kernel functions for driver and device development stuff . if there's such a feature it is very good, and if there something for this kind that you know please refer me to some reference and show me some snippet . No, it can't do such things. At least it isn't embedded in the kernel - in theory that might be possible, but given the timing-constraints and concurrency-requirements, it's not really feasible. Diez -- http://mail.python.org/mailman/listinfo/python-list
Re: simple splash screen?
NighterNet wrote: cut Thanks it help. Sorry about that, I was just wander what kind of answer and if there are other methods to learn it. Is there a way to position image to the center screen? Yes there is, just start reading from here: http://effbot.org/tkinterbook/ Though because Python 3 has done some module reorganisation/renaming, Tkinter is now called tkinter. -- MPH http://blog.dcuktec.com 'If consumed, best digested with added seasoning to own preference.' -- http://mail.python.org/mailman/listinfo/python-list
Re: how to embed the python interpreter into web App (Mehndi, Sibtey)
On Jul 29, 1:11 pm, Ryniek90 rynie...@gmail.com wrote: Hi All I am trying to embed the python interpreter in to a web app but could not get the way, any one can suggest me how to do this. Thanks, Sibtey Mehdi This e-mail (and any attachments), is confidential and may be privileged. It may be read, copied and used only by intended recipients. Unauthorized access to this e-mail (or attachments) and disclosure or copying of its contents or any action taken in reliance on it is unlawful. Unintended recipients must notify the sender immediately by e-mail/phone delete it from their system without making any copies or disclosing it to a third person. Here's example:http://try-python.mired.org/ Contact with author of that website/webapp. Good luck. Or you can look at the code for Crunchy: http://code.google.com/p/crunchy Note however that this will result in something that is not secure... To quote the try-python site: My ISP (idiom.com) provides a sandbox inside a FreeBSD Jail... André -- http://mail.python.org/mailman/listinfo/python-list
IDLE Config Problems
I am just getting started with Python and have installed v. 2.5.4 Idle version 1.2.4 I can't seem to get the idle to display text. It seems as if the install went fine. I start up the idle and the screen is blank. No text. It seems as if I can type on the screen but I just can't see the characters. I go to the config menu and it bombs and brings up the Visual Studio debugger. The computer that I am trying to install it on is a windows xp laptop serv pack 2. I have a workstation here that I am using also with the same os and the idle works fine. Any hints as to what might be interfering with the idle config. Thanks Russ Russell Davis PP, AICP, GISP GIS Administrator State of New Jersey Pinelands Commission Office of Land Use and Technology GIS Laboratory Po Box 7 New Lisbon, NJ 08064 Phone 609-894-7300 Fax 609-894-7330 russ.da...@njpines.state.nj.us -- http://mail.python.org/mailman/listinfo/python-list
Re: set variable to looping index?
Martin wrote:
Hi,
I am trying to set the return value from a function to a name which I
grab from the for loop. I can't work out how I can do this without
using an if statement...
for f in var1_fn, var2_fn, var3_fn:
if f.split('.')[0] == 'var1':
var1 = call_some_function(f)
.
.
.
etc
Really I would like to remove the need for this if loop and I am sure
there is a simple way I am missing?
Many thanks
Martin
Is this a real problem, or is it a programming puzzle? If it's the
latter, maybe someone else can help.
But if it's a real problem, give us some context, and maybe we can
figure out how to help.
If I took this fragment at face value, I'd simply replace it by:
var1 = call_some_function(var1_fn)
var2 = call_some_function(var2_fn)
var3 = call_some_function(var3_fn)
Is this fragment part of a function definition, or is it top-level? Are
there really exactly three var*_fn objects, or might there be an
arbitrary number of them? Do you want to tell us the types of these
three objects? Is there content really tied directly to their name?
Did they get their values from literals, or were they computed at some
other point?
DaveA
--
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Re: set variable to looping index?
On Wed, 29 Jul 2009 19:56:28 +0100, Martin mdeka...@gmail.com wrote:
Hi,
I am trying to set the return value from a function to a name which I
grab from the for loop. I can't work out how I can do this without
using an if statement...
for f in var1_fn, var2_fn, var3_fn:
if f.split('.')[0] == 'var1':
var1 = call_some_function(f)
.
.
.
etc
Really I would like to remove the need for this if loop and I am sure
there is a simple way I am missing?
It's a little hard to tell what you actually want from your description,
but it looks like you're fighting the language unnecessarily here. If
you have a sequence of functions that you want a sequence of results
out of, you should be thinking in terms of a sequence type. A list,
in other words.
results = []
for f in fn1, fn2, fn3:
results.append(f())
--
Rhodri James *-* Wildebeest Herder to the Masses
--
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Re: Differences Between Arrays and Matrices in Numpy
On Wed, 29 Jul 2009 16:23:33 -0400, Nanime Puloski wrote: What are some differences between arrays and matrices using the Numpy library? Matrices are always two-dimensional, as are slices of them. Matrices override mulitplication and exponentiation to use matrix multiplication rather than element-wise multiplication. When would I want to use arrays instead of matrices and vice versa? Use a matrix if you want a matrix, i.e. a linear transformation. Otherwise, use an array. -- http://mail.python.org/mailman/listinfo/python-list
Re: set variable to looping index?
On Jul 29, 11:02 pm, Rhodri James rho...@wildebst.demon.co.uk
wrote:
On Wed, 29 Jul 2009 19:56:28 +0100, Martin mdeka...@gmail.com wrote:
Hi,
I am trying to set the return value from a function to a name which I
grab from the for loop. I can't work out how I can do this without
using an if statement...
for f in var1_fn, var2_fn, var3_fn:
if f.split('.')[0] == 'var1':
var1 = call_some_function(f)
.
.
.
etc
Really I would like to remove the need for this if loop and I am sure
there is a simple way I am missing?
It's a little hard to tell what you actually want from your description,
but it looks like you're fighting the language unnecessarily here. If
you have a sequence of functions that you want a sequence of results
out of, you should be thinking in terms of a sequence type. A list,
in other words.
results = []
for f in fn1, fn2, fn3:
results.append(f())
--
Rhodri James *-* Wildebeest Herder to the Masses
Hi all,
Thanks and apologises I wasn't trying to be cryptic, like all things
when I wrote it I thought it was quite transparent.
All I was trying to do was call a function and return the result to an
a variable. I could admittedly of just done...
var1 = some_function(var1_fn)
var2 = some_function(var2_fn)
var3 = some_function(var3_fn)
where var1_fn, var2_fn, var3_fn are just filenames, e.g. var1_fn =
'x.txt'. But I figured I would try and make it slightly more generic
whilst I was at it, hence my attempt to use the filenames to create
the variable names (hence the loop). I will as suggested try the
dictionary option. I appreciate all the suggestions.
Thanks
Martin
--
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Re: Does python have the capability for driver development ?
Diez B. Roggisch de...@nospam.web.de wrote: MalC0de schrieb: hello there, I've a question : I want to know does python have any capability for using Ring0 and kernel functions for driver and device development stuff . if there's such a feature it is very good, and if there something for this kind that you know please refer me to some reference and show me some snippet . No, it can't do such things. At least it isn't embedded in the kernel - in theory that might be possible, but given the timing-constraints and concurrency-requirements, it's not really feasible. You can write FUSE (file systems in userspace) drivers in python I believe. Not the same as running in ring0 but in most senses a kernel driver... -- Nick Craig-Wood n...@craig-wood.com -- http://www.craig-wood.com/nick -- http://mail.python.org/mailman/listinfo/python-list
Re: set variable to looping index?
30-07-2009 mdeka...@gmail.com wrote:
All I was trying to do was call a function and return the result to an
a variable. I could admittedly of just done...
var1 = some_function(var1_fn)
var2 = some_function(var2_fn)
var3 = some_function(var3_fn)
where var1_fn, var2_fn, var3_fn are just filenames, e.g. var1_fn =
'x.txt'. But I figured I would try and make it slightly more generic
whilst I was at it, hence my attempt to use the filenames to create
the variable names (hence the loop).
Hi,
Then you could also consider using simply lists:
filenames = p'foo', 'bar', baz']
results = []
for name in filenames:
results.append(some_function(name))
If filenames were generated according to a particular pattern, you can
mimic that pattern and generate filenames list using
list-comprehension, e.g.:
filenames = ['file{nr}.txt'.format(nr=nr) for nr in range(13)]
Chreers,
*j
--
Jan Kaliszewski (zuo) z...@chopin.edu.pl
--
http://mail.python.org/mailman/listinfo/python-list
Re: Semaphore Techniques
On Jul 29, 7:14 am, Piet van Oostrum p...@cs.uu.nl wrote: Carl Banks pavlovevide...@gmail.com (CB) wrote: CB On Jul 28, 3:15 pm, John D Giotta jdgio...@gmail.com wrote: I'm looking to run a process with a limit of 3 instances, but each execution is over a crontab interval. I've been investigating the threading module and using daemons to limit active thread objects, but I'm not very successful at grasping the documentation. Is it possible to do what I'm trying to do and if so anyone know of a useful example to get started? CB It seems like you want to limit the number of processes to three; the CB threading module won't help you there because it deals with threads CB within a single process. CB What I'd do is to simply run the system ps to see how many processes CB are running (ps is pretty versatile on most systems and can find CB specifically targeted processes like you program), and exit if there CB are already three. That will surely run into some race conditions. What, the OS might not have gotten around to update the process table to include a process started minutes ago? (He said he was starting the processes over crontab intervals, not that he communicated what he wanted well.) Carl Banks -- http://mail.python.org/mailman/listinfo/python-list
Re: set variable to looping index?
Me wrote: filenames = p'foo', 'bar', baz'] Sorry, should be of course: filenames = ['foo', 'bar', baz'] *j -- Jan Kaliszewski (zuo) z...@chopin.edu.pl -- http://mail.python.org/mailman/listinfo/python-list
Re: set variable to looping index?
On Jul 29, 11:57 pm, Jan Kaliszewski z...@chopin.edu.pl wrote:
30-07-2009 mdeka...@gmail.com wrote:
All I was trying to do was call a function and return the result to an
a variable. I could admittedly of just done...
var1 = some_function(var1_fn)
var2 = some_function(var2_fn)
var3 = some_function(var3_fn)
where var1_fn, var2_fn, var3_fn are just filenames, e.g. var1_fn =
'x.txt'. But I figured I would try and make it slightly more generic
whilst I was at it, hence my attempt to use the filenames to create
the variable names (hence the loop).
Hi,
Then you could also consider using simply lists:
filenames = p'foo', 'bar', baz']
results = []
for name in filenames:
results.append(some_function(name))
If filenames were generated according to a particular pattern, you can
mimic that pattern and generate filenames list using
list-comprehension, e.g.:
filenames = ['file{nr}.txt'.format(nr=nr) for nr in range(13)]
Chreers,
*j
--
Jan Kaliszewski (zuo) z...@chopin.edu.pl
I guess I wanted to keep the function returns in separate arrays in
this case, hence my attempt to make variable names based on the
filenames.
Thanks
Martin
--
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Re: Does python have the capability for driver development ?
MalC0de wrote: hello there, I've a question : I want to know does python have any capability for using Ring0 and kernel functions for driver and device development stuff . if there's such a feature it is very good, and if there something for this kind that you know please refer me to some reference and show me some snippet . thanks - Malc0de Python is interpreted, so the first requirement would be that the interpreter (the python VM to be more precise) would run in the kernel or that there is a way for the interpreter to delegate operations to kernel restricted operations. Most notably access to the memory location of the hardware you want to write a driver for and possibly also a way to pass through a callback function for triggered interrupt coming from the hardware. So technically speaking it shouldn't be impossible. And there is perhaps something to say for being able to write drivers in a readable/easy programming language however I am afraid that if such a beast would be made that it would remain an academical exercise only due to performance constraints. Though I would love to play around with a system where the kernel is essentially only a python interpreter, with full raw access to the hardware. But creating such a thing requires more talent and understanding than currently (and probably ever) in my possession. -- MPH http://blog.dcuktec.com 'If consumed, best digested with added seasoning to own preference.' -- http://mail.python.org/mailman/listinfo/python-list
Re: Differences Between Arrays and Matrices in Numpy
Robert Kern wrote: On 2009-07-29 15:23, Nanime Puloski wrote: What are some differences between arrays and matrices using the Numpy library? When would I want to use arrays instead of matrices and vice versa? You will want to ask numpy questions on the numpy mailing list: http://www.scipy.org/Mailing_Lists An overview of how the matrix subclass differs from ndarray, see the documentation: http://docs.scipy.org/doc/numpy/reference/arrays.classes.html#matrix-objects Basically, I suggest that you just use regular arrays always. There is a syntactical convenience to matrix objects, but it does cause incompatibilities with the majority of code that is written for regular arrays. The convenience is usually not worth the cost. Numpy's arrays can have any dimensionality, whereas matrices[http://en.wikipedia.org/wiki/Matrix_%28mathematics%29], typically have two. A single column can represent a vector or a single row can represent a transposed vector. Does the additional cost arise because the commonly used procedures are accessed through numpy's array? Colin W. -- http://mail.python.org/mailman/listinfo/python-list
Re: Does python have the capability for driver development ?
MalC0de wrote: hello there, I've a question : I want to know does python have any capability for using Ring0 and kernel functions for driver and device development stuff . if there's such a feature it is very good, and if there something for this kind that you know please refer me to some reference and show me some snippet . What operating system are you talking about? Most device drivers run at ring 3 (or lower) and not zero. This way if there is a driver crash the whole operating system doesn't freeze. Python is generally considered a high-level language. If you want to play around with drivers.. usb serial.. etc do it at a python level through the existing device drivers. imho the performance of interpreted python isn't compatible with writing block-mode device drivers (hard-disks) and so forth. What hardware do you have that you need to write a device driver for ? Isn't there a device driver available already? or do you mean just a device controller? David -- http://mail.python.org/mailman/listinfo/python-list
Re: Differences Between Arrays and Matrices in Numpy
On 2009-07-29 18:27, Colin J. Williams wrote: Robert Kern wrote: On 2009-07-29 15:23, Nanime Puloski wrote: What are some differences between arrays and matrices using the Numpy library? When would I want to use arrays instead of matrices and vice versa? You will want to ask numpy questions on the numpy mailing list: http://www.scipy.org/Mailing_Lists An overview of how the matrix subclass differs from ndarray, see the documentation: http://docs.scipy.org/doc/numpy/reference/arrays.classes.html#matrix-objects Basically, I suggest that you just use regular arrays always. There is a syntactical convenience to matrix objects, but it does cause incompatibilities with the majority of code that is written for regular arrays. The convenience is usually not worth the cost. Numpy's arrays can have any dimensionality, whereas matrices[http://en.wikipedia.org/wiki/Matrix_%28mathematics%29], typically have two. A single column can represent a vector or a single row can represent a transposed vector. Does the additional cost arise because the commonly used procedures are accessed through numpy's array? Most functions are written to expect that its inputs behave like ndarrays; e.g. a*b is elementwise multiplication rather than matrix multiplication. When you use the matrix subclass, you are basically confining yourself to a smallish ghetto of functions that knows how to deal with matrix semantics. That's a huge cost compared to the relatively small syntactic cost of having to write dot(a,b) instead of (a*b). -- Robert Kern I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth. -- Umberto Eco -- http://mail.python.org/mailman/listinfo/python-list
Re: Does python have the capability for driver development ?
Rodrigo S Wanderley wrote: cut What about user level device drivers? Think the Python VM could communicate with the driver through the user space API. Is there a Python module for that? Sure why not? Look for example to libusb, which provides a userspace environment and pyusb which uses that and provides an interface to Python. -- MPH -- http://mail.python.org/mailman/listinfo/python-list
