Is it Pythonic to use list comprehensions for just side effects?

Question

Think about a function that I\'m calling for its side effects, not return values (like printing to screen, updating GUI, printing to a file, etc.).

def fun_wi         


        

Answer 1

You shouldn't use a list comprehension, because as people have said that will build a large temporary list that you don't need. The following two methods are equivalent:

consume(side_effects(x) for x in xs)

for x in xs:
    side_effects(x)

with the definition of consume from the itertools man page:

def consume(iterator, n=None):
    "Advance the iterator n-steps ahead. If n is none, consume entirely."
    # Use functions that consume iterators at C speed.
    if n is None:
        # feed the entire iterator into a zero-length deque
        collections.deque(iterator, maxlen=0)
    else:
        # advance to the empty slice starting at position n
        next(islice(iterator, n, n), None)

Of course, the latter is clearer and easier to understand.