Subclassing types and __init__ problems

Lucio Torre lucio at
Tue Mar 25 16:21:23 CET 2003

Hello all,

I have subclassed int and i am having some problems.

Python 2.2.2 (#37, Oct 14 2002, 17:02:34) [MSC 32 bit (Intel)] on win32
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 >>> class myclass(int):
...     def __init__(self, param):
...             print param
 >>> i = myclass(1)
 >>> i = myclass([1,2,3])
Traceback (most recent call last):
   File "<stdin>", line 1, in ?
TypeError: int() argument must be a string or a number

I imagine this is an issue with the types/class unification and stuff.

My questions are:
is the previous code supposed to call int.__init__?
how can i make a class so that isinstance(myclass, int) is 1, but im not 
   forced to call int.__init__?

Thanks in advance,


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