python class variable not visible in __init__?

Question

This code produces an error message, which I found surprising:

class Foo(object):
    custom = 1
    def __init__(self, custom=Foo.custom):
        self._custom          


        

Answer 1

What we do instead is the following

class Foo( object ):
    custom = 1
    def __init__( self, arg=None )
        self._custom = self.custom if arg is None else arg

This bypasses the confusing issue of whether or not the name Foo has been defined yet.