python - Terminating subprocess in python2.7 -

i working on windows 8 x64 system

i writing code in using subprocess execute 1 lengthy program while execution fetch output of program , analyse runtime, particular criteria

i want terminate process criteria met, can't done in program want terminate subprocess python

my code looks

class mythread (threading.thread):     def __init__(self, threadi....         ........         .......      def run(self):         self.process= subprocess.popen(cmd,stdout=subprocess.pipe,stderr=subprocess.stdout)         line in iter(p.stdout.readline, b''):             .........................             ......run-time analysis........             .........................             if (criteria_met):                   self.stop()             .........................             ........................     def stop(self):     if self.process not none:         self.process.terminate()         self.process = none 

but error

exception in thread thread-1: traceback (most recent call last):   file "c:\python27\lib\threading.py", line 551, in __bootstrap_inner     self.run()   file "vb_extraction.py", line 57, in run     self.process.kill()   file "c:\python27\lib\subprocess.py", line 1019, in terminate     _subprocess.terminateprocess(self._handle, 1) windowserror: [error 5] access denied 

what cause of issue? how can terminate process before completing?

call .poll() check whether process still running:

if self.process not none , self.process.poll() none: # still running     self.process.terminate() # or .kill() if doesn't terminate     self.process.communicate() # close pipes, wait completion     self.process = none