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Is this the expected behaviour?
When I run this script, it reads only once, but I expected once per line with
bufsize=1.

What I am trying to do is display the output of a slow process in a tkinter
window as it runs. Right now, the process runs to completion, then display the
result.

import subprocess

com = ['/bin/ls', '-l', '/usr/bin']
with subprocess.Popen(com, bufsize=1, stdout=subprocess.PIPE,
stderr=subprocess.STDOUT) as proc:
print('out: ' + str(proc.stdout.read(), 'utf8'))


Thanks.

--
Yves. http://www.SollerS.ca/
http://ipv6.SollerS.ca
http://blog.zioup.org/

On Sat, Jan 21, 2012 at 9:45 PM, <> wrote:
> Is this the expected behavior?

Yes. `.read()` [with no argument] on a file-like object reads until
EOF. See http://docs.python.org/library/stdtypes.html#file.read

> When I run this script, it reads only once, but I expected once per line
> with bufsize=1.

You want proc.stdout.readline().
http://docs.python.org/library/stdty...#file.readline

> What I am trying to do is display the output of a slow process in a tkinter
> window as it runs. Right now, the process runs to completion, then display
> the result.
>
> Â* Â*import subprocess
>
> Â* Â*com = ['/bin/ls', '-l', '/usr/bin']
> Â* Â*with subprocess.Popen(com, bufsize=1, stdout=subprocess.PIPE,
> stderr=subprocess.STDOUT) as proc:
> Â* Â* Â* Â*print('out: ' + str(proc.stdout.read(), 'utf8'))

Cheers,
Chris

On 2012-01-22 00:27, Chris Rebert wrote:
> On Sat, Jan 21, 2012 at 9:45 PM,<> wrote:
>> Is this the expected behavior?
>
> Yes. `.read()` [with no argument] on a file-like object reads until
> EOF. See http://docs.python.org/library/stdtypes.html#file.read

Right, got it now.

> You want proc.stdout.readline().

Yes, or a for loop, this works for me now:


import subprocess

com = ['/bin/ls', '-l', '/usr/bin']
with subprocess.Popen(com, stdout=subprocess.PIPE,
stderr=subprocess.STDOUT) as proc:
for line in proc:
print('out: ' + str(line, 'utf8'))



--
Yves. http://www.SollerS.ca/
http://ipv6.SollerS.ca
http://blog.zioup.org/

import subprocess

com = ['/bin/ls', '-l', '/usr/bin']
with subprocess.Popen(com, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
as proc:
for line in proc.stdout:
print('out: ' + str(line, 'utf8'))

--
Yves. http://www.SollerS.ca/
http://ipv6.SollerS.ca
http://blog.zioup.org/