I am trying to make a docstring that will accept replacement fields as follows

def run_tests(args):
    """run tests on methods in {0}

    usage: {0} --tests
    """.format(__file__)
    pass

but when I run help(run_tests) in the interpreter, I do not get the docstring. If I remove {} and .format() the docstring returns as expected.

I would like to see the output something like:

Help on function run_tests in module myfile:

run_tests(args)
    runs tests on methods in myfile.py

    usage:  myfile.py --tests

Is there a way to do this in Python 3?