_bool.py 文件源码

def __strict_strtobool(value):
        from distutils.util import strtobool

        if isinstance(value, bool):
            return value

        try:
            lower_text = value.lower()
        except AttributeError:
            raise ValueError("invalid value '{}'".format(str(value)))

        binary_value = strtobool(lower_text)
        if lower_text not in ["true", "false"]:
            raise ValueError("invalid value '{}'".format(str(value)))

        return bool(binary_value)