Suppress stdout / stderr print from Python functions

Question

I have a Python script that is using some closed-box Python functions (i.e. I can\'t edit these functions) provided by my employer. When I call these functions, they are pri

Answer 1

My solution is similar to yours but uses contextlib and is a little shorter and easier to understand (IMHO).

import contextlib


@contextlib.contextmanager
def stdchannel_redirected(stdchannel, dest_filename):
    """
    A context manager to temporarily redirect stdout or stderr

    e.g.:


    with stdchannel_redirected(sys.stderr, os.devnull):
        if compiler.has_function('clock_gettime', libraries=['rt']):
            libraries.append('rt')
    """

    try:
        oldstdchannel = os.dup(stdchannel.fileno())
        dest_file = open(dest_filename, 'w')
        os.dup2(dest_file.fileno(), stdchannel.fileno())

        yield
    finally:
        if oldstdchannel is not None:
            os.dup2(oldstdchannel, stdchannel.fileno())
        if dest_file is not None:
            dest_file.close()

The context for why I created this is at this blog post. Similar to yours I think.

I use it like this in a setup.py:

with stdchannel_redirected(sys.stderr, os.devnull):
    if compiler.has_function('clock_gettime', libraries=['rt']):
        libraries.append('rt')