def is_installable_dir(path):
    'Return True if `path` is a directory containing a setup.py file.'
    if (not os.path.isdir(path)):
        return False
    setup_py = os.path.join(path, 'setup.py')
    if os.path.isfile(setup_py):
        return True
    return False
Return True if `path` is a directory containing a setup.py file.
def is_installable_dir(path):
    
    if (not os.path.isdir(path)):
        return False
    setup_py = os.path.join(path, 'setup.py')
    if os.path.isfile(setup_py):
        return True
    return False