On Tue, 14 Jun 2005, Pujo Aji wrote:
> I have code like this:
>
> class A:
> def __init__(self,j):
> self.j = j
>
> def something(self):
> print self.j
> print i # PROBLEM is here there is no var i in class A
> but it works ???
>
> if __name__ == '__main__':
> i = 10
> a = A(5)
> a.something()
>
> I don't define global i but it will takes var i from outside of class A.
>
> Can somebody explain this ???
The i is 'global' by placement so it can be read.
But you can't assign it in a.something(). If you do:
class A:
def __init__(self,j):
self.j = j
def something(self):
print self.j
i = 11 # makes a new local i in something
print i
if __name__ == '__main__':
i = 10
a = A(5)
a.something()
print 'i = ', i # prints the same old global i = 10
You'll find you made a new i in something and your i = 10 remains the same.
But, if you want to change the global i, in something, then it's time
for the global declaration:
def something(self):
global i
print self.j
i = 11 # changes the global i
print i
Hope this helps. I had the same confusion long ago and this list helped me.
Marilyn Davis
>
> pujo
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> http://mail.python.org/mailman/listinfo/tutor
>
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