John Nagle wrote:
Here's an obscure bit of Python semantics which
is close to being a bug:
>>> class t(object) :
... classvar = 1
...
... def fn1(self) :
... print("fn1: classvar = %d" % (self.classvar,))
... self.classvar = 2
... print("fn1: classvar = %d" % (self.classvar,))
I don't think it's a bug.
None would name a class attribute and an instance attribute with the
same name. So I'm assuming that you want to assign 2 to the *class*
attribute (since it's named classvar :o) ).
You just did it wrong, self.classvar=2 creates the instance attribute
classvar. This is easly fixed by using some well choosen coding rules:
when working with class attributes within an instance either :
always write t.classvar
or
always write self.__class__.classvar
Problem solved. You could ask for python to reject self.classvar but
that would break to OO lookup algo (== an instance has acces to its
class attributes).
JM
--
http://mail.python.org/mailman/listinfo/python-list
