In python, can I redirect the output of print function to stderr?

python python-2.7 stderr
waitingkuo picture waitingkuo · Apr 7, 2013 · Viewed 14.1k times · Source

There're lots of print function (python 2.7) in my program. Is there any way I can add a few lines then all the output can be redirected to stderr? What I want is python codes but not linux pipeline.

For example, my program is like:

print 'hello world'

I would like to add some codes like:

redirect_output_to_stderr()
print 'hello world'

Then all the output can be redirected to stderr.

I know print >> sys.stderr, 'hello world' can achieve my goal, but is it any way that can prevent from modifying the existed codes?

Answer

Roland Smith picture Roland Smith · Apr 7, 2013

In python 2.7 you can do:

import sys

print >> sys.stderr, "To stderr."

Or you can import the behavior from 3.x:

from __future__ import print_function
import sys

print('To stderr.', file=sys.stderr)

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