Threading in Python, Please check the script
Robert Clove
cloverobert at gmail.com
Wed Jan 14 07:11:35 EST 2015
Can u provide me the pseudo script.
On Wed, Jan 14, 2015 at 4:10 PM, Dave Angel <davea at davea.name> wrote:
> On 01/14/2015 01:22 AM, Robert Clove wrote:
>
>> Hi All,
>>
>>
> In any new thread, you should specify what versions of Python and OS
> you're using. I'll assume Python 2.7 and Linux for this message.
>
> I have made a script in which i have started two thread named thread 1 and
>> thread 2.
>> In thread 1 one function will run named func1 and in thread 2 function 2
>> will run named func 2.
>> Thread 1 will execute a command and wait for 60 seconds.
>> Thread 2 will run only till thread 1 is running .
>> Again after that the same process continues in while after a break of 80
>> Seconds.
>>
>> I am a beginner in python.
>> Please suggest what all i have done wrong and how to correct it.
>>
>>
>> #!/usr/bin/python
>>
>> import threading
>> import time
>> import subprocess
>> import datetime
>> import os
>> import thread
>>
>> thread.start_new_thread( print_time, (None, None))
>> thread.start_new_thread( print_time1, (None, None))
>>
>
> In these two lines you're referencing a function that hasn't been defined
> yet. This top-level code should be moved to the end of the file, after the
> if __name__ = "__main__": line
>
> Or just drop it, since you've got a second set of code also trying to
> create new threads.
>
> command= "strace -o /root/Desktop/a.txt -c ./server"
>> final_dir = "/root/Desktop"
>> exitflag = 0
>> # Define a function for the thread
>> def print_time(*args):
>> os.chdir(final_dir)
>> print "IN first thread"
>> proc = subprocess.Popen(command,shell=True,stdout=subprocess.PIPE,
>> stderr=subprocess.PIPE)
>> proc.wait(70)
>> exitflag=1
>>
>
> You just set a local variable, not the global one. So it won't be visible
> in the other thread. If you must rebind a top-level variable from a
> function, you need to use the 'global' declaration in your function.
>
>
>
>> def print_time1(*args):
>> print "In second thread"
>> global exitflag
>> while exitflag:
>> thread.exit()
>> #proc =
>> subprocess.Popen(command1,shell=True,stdout=subprocess.PIPE,
>> sterr=subprocess.PIPE)
>>
>>
>>
>> # Create two threads as follows
>> try:
>> while (1):
>> t1=threading.Thread(target=print_time)
>> t1.start()
>> t2=threading.Thread(target=print_time1)
>> t2=start()
>> time.sleep(80)
>> z = t1.isAlive()
>> z1 = t2.isAlive()
>> if z:
>> z.exit()
>> if z1:
>> z1.exit()
>> threading.Thread(target=print_time1).start()
>> threading.Thread(target=print_time1).start()
>>
>
> What are you trying to do in those two lines? If nothing else, they'll
> give an indentation error. But if you fix that, you'll still have the
> potential problem of creating more and more threads as you loop around.
>
> print "In try"
>> except:
>>
>
> Bare excepts are "evil." Your user can't tell what went wrong, from a
> syntax error to the user hitting control-C. Even if you can't handle a
> particular kind of exception, at least have the courtesy of telling the
> user what went wrong.
>
> print "Error: unable to start thread"
>>
>>
>>
>>
> I'm sure there are other things, but these popped out at me.
>
> --
> DaveA
> --
> https://mail.python.org/mailman/listinfo/python-list
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-list/attachments/20150114/1e454e91/attachment.html>
More information about the Python-list
mailing list