Comment on Python Performance: Why 'if not list' is 2x Faster Than Using len()
jerkface@lemmy.ca 6 days agoTruthiness is so fundamental, all values have a truthiness, whether they are bool or not. Even in C, int x = value(); if (!x) x_is_not_zero(); is valid and idiomatic.
iAvicenna@lemmy.world 6 days ago
I don’t know, it throws me off but perhaps because I always use len in this context. Is there any generally applicable practical reason why one would prefer “not” over len? Is it just compactness and being pythonic?
jerkface@lemmy.ca 6 days ago
iAvicenna@lemmy.world 6 days ago
I feel like that only serves the purpose up to the point that methods are not over reaching otherwise then it turns into remembering what a method does for a bunch of unrelated objects.
sugar_in_your_tea@sh.itjust.works 5 days ago
lenalso works on a dict.The point stands. If you want to check if a value is “empty,” use the check for whether it’s “empty.” In Python, that’s
not. If you care about different types of empty (e.g.Nonevs[]vs{}), then make those checks explicit. That reads a lot better than doing an explicit check where the more common “empty” check would be correct, and it also make it a lot more obvious when you’re doing something special.