Why does python use 'else' after for and while loops?

Question

I understand how this construct works:

for i in range(10):
    print(i)

    if i == 9:
        print(\"Too big - I\'m         


        

Answer 1

Since the technical part has been pretty much answered, my comment is just in relation with the confusion that produce this recycled keyword.

Being Python a very eloquent programming language, the misuse of a keyword is more notorious. The else keyword perfectly describes part of the flow of a decision tree, "if you can't do this, (else) do that". It's implied in our own language.

Instead, using this keyword with while and for statements creates confusion. The reason, our career as programmers has taught us that the else statement resides within a decision tree; its logical scope, a wrapper that conditionally return a path to follow. Meanwhile, loop statements have a figurative explicit goal to reach something. The goal is met after continuous iterations of a process.

if / else indicate a path to follow. Loops follow a path until the "goal" is completed.

The issue is that else is a word that clearly define the last option in a condition. The semantics of the word are both shared by Python and Human Language. But the else word in Human Language is never used to indicate the actions someone or something will take after something is completed. It will be used if, in the process of completing it, an issue rises (more like a break statement).

At the end, the keyword will remain in Python. It's clear it was mistake, clearer when every programmer tries to come up with a story to understand its usage like some mnemonic device. I'd have loved if they have chosen instead the keyword then. I believe that this keyword fits perfectly in that iterative flow, the payoff after the loop.

It resembles that situation that some child has after following every step in assembling a toy: And THEN what Dad?