strutils.py 文件源码

def bool_from_string(value):
    """Interpret string value as boolean.

    Returns True if value translates to True otherwise False.
    """
    if isinstance(value, six.string_types):
        value = six.text_type(value)
    else:
        msg = "Unable to interpret non-string value '%s' as boolean" % (value)
        raise ValueError(msg)

    value = value.strip().lower()

    if value in ['y', 'yes', 'true', 't', 'on']:
        return True
    elif value in ['n', 'no', 'false', 'f', 'off']:
        return False

    msg = "Unable to interpret string value '%s' as boolean" % (value)
    raise ValueError(msg)