[Python-Dev] "not an acceptable base type"?

[Skip Montanaro]

Are strings not yet subclassable or do I just need to "cvs up"?

    >>> class string(str):
    ...   pass
    ... 
    Traceback (most recent call last):
      File "<stdin>", line 1, in ?
    TypeError: type 'str' is not an acceptable base type
    >>> "".__class__ == str
    1

Thx,

Skip