No shadowing in Python when using with-statement?

Asked Jul 08 '14 at 08:38

Active Jul 08 '14 at 08:38

Viewed 17 times

Consider the following Python code:

class Test(object):
    def __init__(self,name):
        self.name = name
    def __enter__(self):
        return self
    def __exit__(self,type,value,trace):
        return True

t = Test("a")
with Test("b") as t:
    print t.name
print t.name

I would have expected the output to be b,a, but it actually is b,b.

Is there no such thing as shadowing in Python? Is this really expected behavior?

asked Jul 08 '14 at 08:38

muffel

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The variables used in `with` statement are not cleaned up, so you've no reference to `Test("a")` now, hence it prints b, b. – Ashwini Chaudhary Jul 08 '14 at 08:49
1

No, Python's scoping rules do not allow for shadowing. You have local, closure and global scopes *only*. – Martijn Pieters Jul 08 '14 at 08:49
As such, the `with .. as` binding is local to the current scope, exactly the same way that `for ... in ` binds locally, not just for the `for` suite. – Martijn Pieters Jul 08 '14 at 08:50

No shadowing in Python when using with-statement?

0 Answers0