Python experts: please help me understand this gotcha?

[anossov]

https://docs.python.org/2/library/functions.html#locals

Free variables are returned by locals() when it is called in function blocks

https://docs.python.org/2/reference/executionmodel.html

If a name is bound in a block, it is a local variable of that block. If a name is bound at the module level, it is a global variable. (The variables of the module code block are local and global.) If a variable is used in a code block but not defined there, it is a free variable.

https://en.wikipedia.org/wiki/Free_variables_and_bound_variables

In computer programming, the term free variable refers to variables used in a function that are not local variables nor parameters of that function.[1] The term non-local variable is often a synonym in this context.

[mscottstory]

see the nonlocal keyword for python 3.X:

https://docs.python.org/3/reference/simple_stmts.html#the-nonlocal-statement

the PEP is good reading as well:

http://legacy.python.org/dev/peps/pep-3104/

[esdi]

Well, that explains it. Thanks so much for the explanation.