Jupyter Snippet CB2nd 01_timeit

4.1. Evaluating the time taken by a command in IPython

n = 100000

%timeit sum([1. / i**2 for i in range(1, n)])

21.6 ms ± 343 µs per loop (mean ± std. dev. of 7 runs,
    10 loops each)

%%timeit s = 0.
for i in range(1, n):
    s += 1. / i**2

22 ms ± 522 µs per loop (mean ± std. dev. of 7 runs,
    10 loops each)

import numpy as np

%timeit np.sum(1. / np.arange(1., n) ** 2)

160 µs ± 959 ns per loop (mean ± std. dev. of 7 runs,
    10000 loops each)