Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.python > #52877

RE: Running a command line program and reading the result as it runs

Show key headers only | View raw

> >> I'm using Python 2.7 under Windows and am trying to run a command line
> >> program and process the programs output as it is running. A number of
> >> web searches have indicated that the following code would work.
> >>
> >> import subprocess
> >>
> >> p = subprocess.Popen("D:\Python\Python27\Scripts\pip.exe list -o",
> >>                      stdout=subprocess.PIPE,
> >>                      stderr=subprocess.STDOUT,
> >>                      bufsize=1,
> >>                      universal_newlines=True,
> >>                      shell=False)
> >> for line in p.stdout:
> >>     print line
> >>
> >> When I use this code I can see that the Popen works, any code between
> >> the Popen and the for will run straight away, but as soon as it gets to
> >> the for and tries to read p.stdout the code blocks until the command
> >> line program completes, then all of the lines are returned.
> >>
> >> Does anyone know how to get the results of the program without it
> >> blocking?

Try this:

p = subprocess.Popen(args, stdout=subprocess.PIPE)
for line in p.stdout:
    print(line)
p.wait()

jlc

Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Running a command line program and reading the result as it runs Ian Simcock <Ian.Simcock@Internode.on.net> - 2013-08-22 15:21 +0930
  Re: Running a command line program and reading the result as it runs Chris Angelico <rosuav@gmail.com> - 2013-08-22 16:22 +1000
    Re: Running a command line program and reading the result as it runs Ian Simcock <Ian.Simcock@Internode.on.net> - 2013-08-23 00:56 +0930
      Re: Running a command line program and reading the result as it runs Chris Angelico <rosuav@gmail.com> - 2013-08-23 01:33 +1000
        Re: Running a command line program and reading the result as it runs Ian Simcock <Ian.Simcock@Internode.on.net> - 2013-08-23 16:22 +0930
        Re: Running a command line program and reading the result as it runs Grant Edwards <invalid@invalid.invalid> - 2013-08-23 14:02 +0000
  Re: Running a command line program and reading the result as it runs Rob Wolfe <rw@smsnet.pl> - 2013-08-22 23:14 +0200
    Re: Running a command line program and reading the result as it runs Ian Simcock <Ian.Simcock@Internode.on.net> - 2013-08-23 16:31 +0930
  Re: Running a command line program and reading the result as it runs Gertjan Klein <gklein@xs4all.nl> - 2013-08-23 11:32 +0200
  Re: Running a command line program and reading the result as it runs Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-08-23 11:53 +0200
  Re: Running a command line program and reading the result as it runs Antoon Pardon <antoon.pardon@rece.vub.ac.be> - 2013-08-23 12:34 +0200
  RE: Running a command line program and reading the result as it runs "Joseph L. Casale" <jcasale@activenetwerx.com> - 2013-08-23 10:50 +0000
  Re: Running a command line program and reading the result as it runs Peter Otten <__peter__@web.de> - 2013-08-23 13:14 +0200
    Re: Running a command line program and reading the result as it runs Gertjan Klein <gklein@xs4all.nl> - 2013-08-23 14:03 +0200
    Re: Running a command line program and reading the result as it runs Ian Simcock <Ian.Simcock@Internode.on.net> - 2013-08-24 19:06 +0930
  Re: Running a command line program and reading the result as it runs random832@fastmail.us - 2013-08-23 12:04 -0400
  Re: Running a command line program and reading the result as it runs Peter Otten <__peter__@web.de> - 2013-08-23 18:39 +0200

csiph-web