# performance.py
from time import time

mx = 5000

t = time()  # start time for the for loop
floop = []
for a in range(1, mx):
    for b in range(a, mx):
        floop.append(divmod(a, b))
print('for loop: {:.4f} s'.format(time() - t))  # elapsed time


t = time()  # start time for the list comprehension
compr = [
    divmod(a, b) for a in range(1, mx) for b in range(a, mx)]
print('list comprehension: {:.4f} s'.format(time() - t))


t = time()  # start time for the generator expression
gener = list(
    divmod(a, b) for a in range(1, mx) for b in range(a, mx))
print('generator expression: {:.4f} s'.format(time() - t))


# verify correctness of results and number of items in each list
print(
    floop == compr == gener, len(floop), len(compr), len(gener)
)