__init__.py 文件源码

def no(mytype, argnums=(1,)):
    """
    A shortcut for the disallow_types decorator that disallows only one type
    (in any position in argnums).

    Example use:

    >>> class newstr(object):
    ...     @no('bytes')
    ...     def __add__(self, other):
    ...          pass

    >>> newstr(u'1234') + b'1234'     #doctest: +IGNORE_EXCEPTION_DETAIL
    Traceback (most recent call last):
      ...
    TypeError: argument can't be bytes

    The object can also be passed directly, but passing the string helps
    to prevent circular import problems.
    """
    if isinstance(argnums, Integral):
        argnums = (argnums,)
    disallowed_types = [mytype] * len(argnums)
    return disallow_types(argnums, disallowed_types)