Python 3.6+statisticsfunction

statistics.harmonic_mean

mean

Harmonic mean (reciprocal of the mean of reciprocals).

Syntax

statistics.harmonic_mean(data)

It fits averaging rates over equal amounts of work: half the distance at 60 and half at 30 averages 40, not 45. A single zero makes the whole result zero — the algorithm short-circuits there and never validates the remaining values — while a negative value raises StatisticsError. The weights argument arrived in 3.10.

Examples

# Python 3.10+
import statistics
print(statistics.harmonic_mean([1, 2, 4]))   # → 1.7142857142857142
print(statistics.harmonic_mean([10, 40]))   # → 16.0
print(statistics.mean([60, 30]), statistics.harmonic_mean([60, 30]))   # → 45 40.0
print(statistics.harmonic_mean([40, 60], weights=[5, 30]))   # → 56.0
print(statistics.harmonic_mean([1, -2]))   # → StatisticsError

See also

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