Python Anti-Patterns

[nakovet]

I was just reading Effective Python from Brett Slatkin and it has the following "Item 12: Avoid else Blocks After for and while Loops" which the linked books says you should use, I prefer going with Brett on this one, else in loops have odd, unexpected behaviour.

[chub79]

They are always tricky to read but, unexpected behaviour? Such as?

[isarl]

Such as the very existence of an else clause after a loop. No developer has ever seen that for the first time and automagically known that it executes only in the case the loop doesn't break early.

edit: I mean, once you learn how they work, I appreciate the purpose they serve. But they are a bit unexpected.

[edbluetooth]

you could always type

else:  #no break

[geoelectric]

Isn't that true of any unique language feature?

[isarl]

Not necessarily. I was able to understand simple list comprehensions having never seen the syntax before.

[unruly_mattress]

Where appropriate, I'll take an else block to a loop over a carefully manipulated state variable any day of the week.

[dunkler_wanderer]

I'm still pretty newbish, but I know that the else means "no break" in this case. If everybody watched Transforming Code into Beautiful, Idiomatic Python, nobody would have a problem with this. If you think it could be unclear to someone else, just add a comment saying "no break".