Python 3.10+statisticsfunction

statistics.correlation

relationships

Pearson's (or Spearman's) correlation coefficient of two datasets, −1..1 (3.10+).

Syntax

statistics.correlation(x, y)

It detects straight-line relationships only: y = x² on a symmetric dataset scores near zero despite being perfectly determined, and a high score says nothing about cause. Both inputs must have the same length and at least two values, and a constant sequence (zero spread) raises StatisticsError. Spearman's version requires method='ranked', which exists only from 3.12.

Examples

import statistics
print(statistics.correlation([1, 2, 3], [2, 4, 6]))   # → 1.0
print(statistics.correlation([1, 2, 3], [6, 4, 2]))   # → -1.0
print(statistics.correlation([1, 2, 3, 4], [1, 3, 2, 4]))   # → 0.8
print(statistics.correlation([1, 1, 1], [1, 2, 3]))   # → StatisticsError

# Python 3.12+
import statistics
print(statistics.correlation([1, 2, 3], [10, 30, 20], method='ranked'))   # → 0.5

See also

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