pythonで"True", "False"をboolに変換する

utils.py

# -*- coding: utf-8 -*-

from ast import literal_eval

def parse_bool(value):
    """test
    >>> parse_bool("True")
    True
    >>> parse_bool("False")
    False
    >>> parse_bool(True)
    True
    >>> parse_bool(False)
    False
    >>> parse_bool("1")
    Traceback (most recent call last):
    ...
    ValueError: malformed value
    >>> parse_bool("true")
    Traceback (most recent call last):
    ...
    ValueError: malformed string
    >>> parse_bool("false")
    Traceback (most recent call last):
    ...
    ValueError: malformed string
    >>> parse_bool("'hgoehoge'")
    Traceback (most recent call last):
    ...
    ValueError: malformed value
    >>> parse_bool("")
    Traceback (most recent call last):
    ...
    SyntaxError: unexpected EOF while parsing
    >>> parse_bool("hogehoge")
    Traceback (most recent call last):
    ...
    ValueError: malformed string
    """

    if isinstance(value, str):
        value = literal_eval(value)
    if not isinstance(value, bool):
        raise ValueError('malformed value')
    return value


if __name__ == "__main__":
    import doctest
    doctest.testmod()