Silence stdout (python)

silence_output.py

#
# Sometime, specifically in your tests, you want to silence the
# standard output or be able to read the standard output of a function
# to test what's printed. Here is some recipe to do that.
#
#

import cStringIO as StringIO
import sys

from contextlib import contextmanager

@contextmanager
def SilenceStdout(new_stream=None):
  if new_stream is None:
    new_stream = StringIO.StringIO()

  old_stream, sys.stdout = sys.stdout, new_stream
  try:
    yield sys.stdout
  finally:
    sys.stdout = old_stream
    new_stream.seek(0)


# test
if __name__ == '__main__':
  def verbose_function():
    print 'This function print stuff'

  with SilenceStdout():
    verbose_function()

  with SilenceStdout() as fdout:
    verbose_function()

  if 'stuff' in fdout.read():
    print 'the word "stuff" was found!'