Re: How to schedule system calls with Python
Again another great suggestion. I was not aware of the multiprocessing module, and I'm not (yet) sure if I understand why I should use instead of multithreading as explained by a previous post. http://docs.python.org/library/multiprocessing.html First paragraph... -- Thanks, --Minesh -- http://mail.python.org/mailman/listinfo/python-list
Re: subprocess hangs on reading stdout
Any ideas? comments on code welcome also. Here's something that I would probably do, there may be better ways. This only works on python2.6 for the terminate() method. import signal import subprocess def timeout_handler(signum, frame): print About to kill process p.terminate() for machine_name in self.alive: cmd = [/bin/remsh, machine_name, 'ps -flu %s' % uid] signal.signal(signal.SIGALRM, timeout_handler) signal.alarm(1) p = subprocess.Popen(cmd,stdout=subprocess.PIPE) (stdout, stderr) = p.communicate() signal.alarm(0) if stdout: print stdout elif stderr: print stderr -- Thanks, --Minesh -- http://mail.python.org/mailman/listinfo/python-list
Re: how to iterate over several lists?
On Fri, Jun 5, 2009 at 10:20 AM, Tomsevenb...@gmail.com wrote:
On Fri, 5 Jun 2009 04:07:19 + (UTC), kj no.em...@please.post
wrote:
Suppose I have two lists, list_a and list_b, and I want to iterate
over both as if they were a single list. E.g. I could write:
for x in list_a:
foo(x)
for x in list_b:
foo(x)
But is there a less cumbersome way to achieve this? I'm thinking
of something in the same vein as Perl's:
for $x in (@list_a, @list_b) {
foo($x);
}
TIA!
kynn
def chain(*args):
return (item for seq in args for item in seq)
for x in chain(list_a, list_b):
foo(x)
--
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If they are the same length, you can try the zip built-in function.
--
Thanks,
--Minesh
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ConfigParser and newlines
I am using ConfigParser to parse a config file and I want to maintain
the newlines, how is it possible. Example given below. BTW, is there
an alternative to configParser, should I use 'exec' instead. Is there
any support for yaml built-in or possibly in the future?
test.cfg
[Foo_Section]
BODY = Line of text 1
Continuing Line of text 1
Executing the code
===
Python 2.5.1 Stackless 3.1b3 060516 (release25-maint, Mar 6 2009, 14:12:34)
[GCC 4.3.0 20080428 (Red Hat 4.3.0-8)] on linux2
Type help, copyright, credits or license for more information.
from ConfigParser import RawConfigParser
config = RawConfigParser()
config.read('test.cfg')
['test.cfg']
config.get('Foo_Section', 'BODY')
'Line of text 1\nContinuing Line of text 1'
===
I was expecting 'Line of text 1\n\nContinuing Line of text 1'
with 2 newlines, how can I achieve that with ConfigParser.
--
Thanks,
./Minesh
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Re: ConfigParser and newlines
Not as best I can tell. From my /usr/lib/python2.5/ConfigParser.py file, around line 441: if line[0].isspace() and cursect is not None and optname: value = line.strip() if value: cursect[optname] = %s\n%s % (cursect[optname], value) That value = line.strip() is what's throwing away your extra newline. Then the if value refuses to add the extra newline because it was a blank line. It looks like this behavior was intentional? Is that a bug? What would be the use cases for stripping newlines unnecessarily. Seems like the configParser is trying to be too clever. -- Thanks, ./Minesh -- http://mail.python.org/mailman/listinfo/python-list
Re: Is there is any way to send messages to chunk of emails ID's concurrently using smptlib
On Mon, May 4, 2009 at 2:01 PM, Piet van Oostrum p...@cs.uu.nl wrote:
gganesh ganesh@gmail.com (g) wrote:
g Hi friends,
g I suppose sendmail() can send mails one by one ,how to send mails
g concurrently ,
g It would be very grateful,if someone could point out a solution.
You can always use twisted which has an smtp library which is used for
concurrency. Not a complete working example but an understanding of
deferreds is required.
Ex:
from twisted.mail import smtp
from twisted.internet import reactor, defer
def sendEmail(to, message, subject=Testing,
_from='f...@bar.com'):
Used to send emails asyncronously to multiple recipients
msg = MIMEText(message)
msg['Subject'] = subject
msg['From'] = _from
msg['To'] = , .join(to)
sending = smtp.sendmail('localhost', _from, to, msg)
sending.addCallback(sendComplete, to).addErrback(sendFailed)
def sendFailed(error):
print Email failed: %r % (error.getTraceback(),)
def sendComplete(result, recipients):
numDelivered, addrInfo = result
print addrInfo
if (numDelivered != len(recipients)):
log.msg(SmtpError, Not all recipients received email %r % addrInfo)
buf = 'TESTING'
sendEmail(to=['t...@spam.com'], message=buf)
--
Thanks,
./Minesh
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Re: parallel/concurrent process in python
On Mon, Mar 9, 2009 at 2:47 PM, ommer.sim...@gmail.com wrote: I'm trying to figure out parallel process python code. Something similar to fork funtion in C. For example, I using sniff tool in scapy to capture packets but i want this to run in the background: --- from scapy.all import * import subprocess import netsnmp pkts=sniff(iface=eth0,filter=UDP,count=100) # This should run in the background print Next Code.' - Next Code. should be printed out right away and does not have to wait for pkts=sniff(...) to finish. Any ideas? Why not use os.fork(), it is the same as C's fork? if os.fork(): # Returns 0 to child, non-zero to parent # Do parent stuff else: # Do child stuff -- Thanks, Minesh Patel -- http://mail.python.org/mailman/listinfo/python-list
Re: parallel/concurrent process in python
os.fork is not cross platform. It is *nix only. Subprocess runs on Windows also. The OP never specified his platform. Just out of curiosity, how is one able to replace an os.fork() call with subprocess and have the child execute multiple statements? I typically see subprocess used for spawning a shell command, piping, etc... -- Thanks, Minesh Patel -- http://mail.python.org/mailman/listinfo/python-list
Concurrent tasklets in Stackless Python
Is there a way for multiple tasklets to run in parallel? I have been following the examples in http://members.verizon.net/olsongt/stackless/why_stackless.html but it seems that tasklets block for data or are scheduled and there is no way to run them concurrently. -- Thanks, Minesh Patel -- http://mail.python.org/mailman/listinfo/python-list
Re: Concurrent tasklets in Stackless Python
On Mon, Mar 9, 2009 at 3:17 PM, Chris Rebert c...@rebertia.com wrote: On Mon, Mar 9, 2009 at 3:05 PM, Minesh Patel min...@gmail.com wrote: Is there a way for multiple tasklets to run in parallel? Seems doubtful (though I'm not an expert). From the Wikipedia article: Stackless microthreads are managed by the language interpreter itself, not the operating system kernel—context switching and task scheduling is done purely in the interpreter. This suggests that only one microthread is ever really being run at any given time. I would venture a guess that the lack of true parallel-ness is probably a design decision deeply ingrained into Stackless and is not changeable. You'd probably have to change to multiprocessing or threads. Thanks Chris, Can you suggest any Python libraries for true parallelism or should I just stick with Python Threads or asyncore Thanks, Minesh -- http://mail.python.org/mailman/listinfo/python-list
Should I use stackless python or threads?
I am trying to figure out the best approach to solve this problem: I want to poll various directories(can be run in the main thread). Once I notice a file has been added to any directory, I grab a lock, spawn a thread to go perform the necessary actions, and then release the lock. -- Thanks for the help, Minesh Patel -- http://mail.python.org/mailman/listinfo/python-list
Re: Should I use stackless python or threads?
On Fri, Mar 6, 2009 at 3:16 PM, Jean-Paul Calderone exar...@divmod.com wrote: On Fri, 6 Mar 2009 14:50:51 -0800, Minesh Patel min...@gmail.com wrote: I am trying to figure out the best approach to solve this problem: I want to poll various directories(can be run in the main thread). Once I notice a file has been added to any directory, I grab a lock, spawn a thread to go perform the necessary actions, and then release the lock. That's not a description of a problem. That's a description of a potential solution. What problem are you trying to solve? I have a build system that is outputting various forms of installations in a particular directory structure, e.g. /pxe-installs, /iso-install, /dd-installs, etc... I need to monitor each directory for the latest install, take it and go perform some tests on a specific machine. I would like these testing tasks to run concurrently for the obvious reasons. Thanks again for the help, Minesh -- http://mail.python.org/mailman/listinfo/python-list
Python patch module
Hi, I was wondering if there is any patch management module for Python. Basically I am looking to only apply a hunk from a patch if the file exists. -- Thanks, Minesh -- http://mail.python.org/mailman/listinfo/python-list
