What does nonlocal do in Python 3.x? To close debugging questions where OP needs nonlocal and doesn't realize it, please use Is it possible to modify variable in python that is in outer, but not g...

Jul 1, 2013 · I'm trying to implement a closure in Python 2.6 and I need to access a nonlocal variable but it seems like this keyword is not available in python 2.x. How should one access nonlocal variables in closures in these versions of python?

Oct 19, 2015 · I'm learning the concepts of programming languages. I found the terminology "nonlocal" in python syntax. What is the meaning of nonlocal in python?

Python 2 had no way to distinguish the intended meaning, so it assumed a fresh variable was wanted. Python 3 defaults to the same behaviour, but allows the other to be used via the nonlocal keyword.

Jan 11, 2014 · The difference is that Python 3 allows you to change the value of the closed-over variable without creating a new variable as a side effect. nonlocal tells the compiler that, despite the assignment happening in an inner block, the variable being …

Jun 1, 2013 · The nonlocal statement causes the listed identifiers to refer to previously bound variables in the nearest enclosing scope. In the third example, the "nearest enclosing scope" just happens to be the global scope.

Jan 23, 2012 · In python 3 it is possible to rebind a non-local variable, though it has to be explicitly defined as nonlocal at the function beginning, if done with regular code.

Mar 29, 2011 · I'm trying to perform some analysis of scope in Python 3 source code and I'm stuck with how the nonlocal statement statement works inside a class definition. As I understand it, the class definition executes its body inside a new namespace (call it dict) and binds the class name to the result of type (name, bases, dict).

Nov 9, 2011 · Additional questions q1, q2 and answers can be found on SO, among even more. The official Python documentation, and PEP 3104 are supposed to explain the details, but they don't seem fully self-explanatory to me. The topic I'm trying to solve is refactoring of code containing nonlocal / global by moving that code up/down one level of hierarchy.

Mar 7, 2012 · @Marcin Just like a seperate object or a nonlocal variable - you have multiple closures/function objects/hand-rolled objects, and either you keep each to exactly one thread or you'll need synchronization.