import numpy as np
import pandas as pd
pd_series = pd.Series(np.random.rand(10**6))
%%timeit
pd_series.sum()
3.73 ms ± 149 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)
%%timeit
np.nansum(pd_series.values)
2.21 ms ± 154 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)
%%timeit
pd_series.sum(skipna=False)
429 µs ± 51.1 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)
%%timeit
pd_series.values.sum()
382 µs ± 42.8 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)
%%timeit
np.sum(pd_series.values)
361 µs ± 39.6 µs per loop (mean ± std. dev. of 7 runs, 1000 loops each)