subclassing "file"

Uwe Mayer merkosh at
Mon Jan 19 17:14:33 CET 2004


when extending a build in class, what does the constructor __init__(...)
have to return?
and how does the constructor call its base-class construtor? (or is this
done automatically?)

I want to derive from "file" to create a class that reads record from a
binary file:

class myFile(file):
        def __init__(self, filename, mode="r", bufsize=-1):

just calling the basename and the constructor does not work:

>>> f = myFile("testfile")
>>> f
<closed file '<uninitialized file>', mode '<uninitialized file>' at ...>

What am I missing?

Thanks for your comments

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