memory management - why is python generator slower than range and itertool repeat? - Stack Overflow

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I stormed up a Youtube short which introduced me to repeat from the itertools. I then decided to compare it to range and repeat but it seem very slow. What could be the reason?

Below is my code

from itertools import repeat
from timeit import timeit

def range_generator(start, stop, step=1):
    while start <= stop:
        yield start
        start += step
        
def for_range():
    for _ in range(999_999_999): ...

def for_repeat():
    for _ in repeat(None, 999_999_999): ...

def for_range_gen():
    for _ in range_generator(1, 999_999_999): ...

range_time = timeit(for_range, number=1)
repeat_time = timeit(for_repeat, number=1)
for_range_gen_time = timeit(for_range_gen, number=1)

print(f"{range_time:.3f}s")
print(f"{repeat_time:.3f}s")
print(f"{for_range_gen_time:.3f}s")

I tried comparing and timing them all and it turned out my custom generator is way too slow compared to range and repeat. Running the script 3 different times, i got;

28.492s
17.067s
121.059s
--------
32.078s
16.321s
148.467s
---------
29.349s
18.025s
126.159s

ChatGPT seem to let me know range and repeat are both implemented in C that's why it much faster than my custom generator. How true is this please?

I expect my custom generator should finish way faster than other functions range_time and repeat_time.

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