197 – Fully consume an iterator

To fully consume an iterator without wasting any memory, use an instance of collections.deque with its maximum length set to 0:

from collections import deque

squares = (n ** 2 for n in range(100))

deque(squares, maxlen=0)

for sq in squares:
    print(sq)
# No output!

Running the code above produces no output because the generator squares is fully consumed by the call to deque.

The deque approach is faster than an empty Python loop because deque is implemented in C whereas the loop runs at the Python level.