How can I suppress stdout logging output for a module I'm importing?

Question

I'm importing a module foo which uses Python's logging module. However, foo produces a huge amount of logging output, and I need to use stdout to communicate important information to the user, which is largely being drowned out by the ridiculous output of the module I'm importing.

How can I disable the module's ability to log to stdout without modifying foo's code? I still want it to log to the files it logs to, but I don't want it logging to stdout.

I have tried the following:

logging.getLogger("foo").propagate = False

and

@contextlib.contextmanager
def nostdout():
    class DummyFile(object):
        def write(self, x): pass
    save_stdout = sys.stdout
    sys.stdout = DummyFile()
    yield
    sys.stdout = save_stdout

with nostdout(): import foo

Answer 1

Try the following:

logging.getLogger(<logger_name_used_in_foo>).propagate = False

Answer 2

I'm referencing this article. In general, if you want to capture anything written to stdout you can use the contextlib in Python 3:

from contextlib import redirect_stdout

f = io.StringIO()
with redirect_stdout(f):
    print('foobar')
    call_annoying_module()
print('Stdout: "{0}"'.format(f.getvalue()))

On Python 3.4 and older, redirect_stdout can be implemented like this:

from contextlib import contextmanager

@contextmanager
def stdout_redirector(stream):
    old_stdout = sys.stdout
    sys.stdout = stream
    try:
        yield
    finally:
        sys.stdout = old_stdout

If the library has any C bindings that print using puts then it gets more complicated. See the article.

The easiest case is when you're running another program using subprocess, then all stdout output can be easily captured.

proc = subprocess.Popen("echo output".split(), stdout=subprocess.PIPE)
std_output, err_output = proc.communicate()