Post

Reuven M. Lerner

@lernerpython.com

Consider this #Python code: x = 100 for i in range(10): x = i ** 2 print(x) What is printed? Answer: 81. Wait, isn't x local, inside of the loop? Shouldn't it be 100? Nope — indentation ≠ scope. Inside of a loop, without a function, you're still in the global scope. Questions?

19/12/24, 10:23 am1 repost17 likes

@dcbriccetti.bsky.social

Have you ever used `nonlocal`, just out of curiosity?

Reuven M. Lerner

@lernerpython.com

Yes, definitely! It's super useful in decorators, using the outer function for storage that sticks around across invocations of the inner functions.

Yes. Do you validate parking? Just kidding. Thanks, TIL.

@kerbart.bsky.social

Inside a function I get the same result. What would be an example where it doesn't work like that?

Reuven M. Lerner

@lernerpython.com

It always works like that in Python. But setting the variable in a function doesn't affect a variable of the same name outside of the function.

Stephen Gruppetta

@stephengruppetta.com

The fact that the same indentation is used for blocks such as loops but also functions often confuses beginners

Rodrigo Girão Serrão 🐍🚀

Ahem, is there a question, there? 🤪

Stephen Gruppetta

@stephengruppetta.com

Just add “Do you think…” at the start and “…?” at the end

Reuven M. Lerner

@lernerpython.com

Oh, great question! The answer is "yes."