use-a-generator / R1729¶
Message emitted:
Use a generator instead '%s(%s)'
Description:
Comprehension inside of 'any', 'all', 'max', 'min' or 'sum' is unnecessary. A generator would be sufficient and faster.
Problematic code:
from random import randint
all([randint(-5, 5) > 0 for _ in range(10)]) # [use-a-generator]
any([randint(-5, 5) > 0 for _ in range(10)]) # [use-a-generator]
Correct code:
from random import randint
all(randint(-5, 5) > 0 for _ in range(10))
any(randint(-5, 5) > 0 for _ in range(10))
Additional details:
By using a generator you can cut the execution tree and exit directly at the first element that is False for all or True for any instead of
calculating all the elements. Except in the worst possible case where you still need to evaluate everything (all values
are True for all or all values are false for any) performance will be better.
Related links:
Created by the refactoring checker.