utils.py 文件源码

def from_key_val_list(value):
    """Take an object and test to see if it can be represented as a
    dictionary. Unless it can not be represented as such, return an
    OrderedDict, e.g.,

    ::

        >>> from_key_val_list([('key', 'val')])
        OrderedDict([('key', 'val')])
        >>> from_key_val_list('string')
        ValueError: need more than 1 value to unpack
        >>> from_key_val_list({'key': 'val'})
        OrderedDict([('key', 'val')])

    :rtype: OrderedDict
    """
    if value is None:
        return None

    if isinstance(value, (str, bytes, bool, int)):
        raise ValueError('cannot encode objects that are not 2-tuples')

    return OrderedDict(value)