Why is Python scoping made the way it is

Question

I understand generally how scoping works in Python for loops. My question is why the design decisions were made in this way. For example:

for foo in xrange(10):
    bar = 2
print(foo, bar)

The above will print (9,2).

T'foo' is really just controlling the loop, and 'bar' was defined inside the loop. I can understand why it might be necessary for 'bar' to be accessible outside the loop (otherwise, for loops would have very limited functionality). 

What I don't understand is why it is necessary for the control variable to remain in scope after the loop exits. I'd appreciate if anyone threw some light at this!

Answer 1

The likeliest answer is that it just to keep the grammar simple.

It hasn't been a stumbling block for adoption, and many have been happy with not having to disambiguate the scope to which a name belongs when assigning to it within a loop construct. 

Variables are not declared within a scope, it is implied by the location of assignment statements. The global keyword exists just for this reason (to signify that assignment is done at a global scope).