Threading in Python, Please check the script

Robert Clove cloverobert at gmail.com
Wed Jan 14 13:11:35 CET 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
>
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