utils.py 文件源码

def import_nose():
    """ Import nose only when needed.
    """
    nose_is_good = True
    minimum_nose_version = (1, 0, 0)
    try:
        import nose
    except ImportError:
        nose_is_good = False
    else:
        if nose.__versioninfo__ < minimum_nose_version:
            nose_is_good = False

    if not nose_is_good:
        msg = ('Need nose >= %d.%d.%d for tests - see '
               'http://nose.readthedocs.io' %
               minimum_nose_version)
        raise ImportError(msg)

    return nose