Question

Refering to Variable Scoping.

I’m trying to figure out what are the differences between those 2.

For example, Anonymous functions in a scheme function has access to the variables local to that function. Does python have this?

Thanks!

Answer 1

In Python variable scope can be either global or function. In Scheme, the scope can be any block.

For example, in Scheme you could define a variable inside a loop, and it wouldn’t be accessible from outside the loop. In Python, the scope being the whole function, this variable would ‘leak’ out of the loop into the rest of the function.

About your specific question: note that anonymous (lambda) functions in Python are horribly limited (just a single expression, no if/then statements, loops, etc.), so you usually define complete (named) inner functions. In this case the scope rules are similar to Scheme: the inner function can access the outer function’s variables (creating a closure), and the outer function can’t access variables defined inside the inner function.

In short: lexical scoping and closures work as expected; just remember that the scoping granularity is per function, not per block.