On Oct 11, 3:04 am, metal <metal...@gmail.com> wrote: > Environment: > > PythonWin 2.5.4 (r254:67916, Apr 27 2009, 15:41:14) [MSC v.1310 32 bit > (Intel)] on win32. > Portions Copyright 1994-2008 Mark Hammond - see 'Help/About PythonWin' > for further copyright information. > > Evil Code: > > class Foo: > def __init__(self, *args): > print args > > Foo(1, 2, 3) # (1, 2, 3), good > > class Bar(tuple): > def __init__(self, *args): > print args > > Bar(1, 2, 3) # TypeError: tuple() takes at most 1 argument (3 given) > > what the heck? I even didn't call tuple.__init__ yet
When subclassing immutable types you'll want to override __new__, and should ensure that the base type's __new__ is called: __ class MyTuple(tuple): __ def __new__(cls, *args): __ return tuple.__new__(cls, args) __ print MyTuple(1, 2, 3) (1, 2, 3) See http://www.python.org/download/releases/2.2.3/descrintro/#__new__ -- http://mail.python.org/mailman/listinfo/python-list
