Python 3.4+statisticsfunction

statistics.variance

spread

Sample variance (the square of stdev, with n−1).

Syntax

statistics.variance(data)

The xbar argument is taken on trust: hand it a value that is not the actual mean and you get a number that is no longer a variance, with no error raised. Use pvariance when the data is a whole population rather than a sample, and note that if you only need to compare spreads the square root is redundant — variance and stdev rank datasets identically.

Examples

import statistics
print(statistics.variance([1, 2, 3, 4, 5]))   # → 2.5
print(statistics.variance([1, 2, 3, 4, 5], xbar=3))  # → 2.5
print(statistics.variance([2, 4, 4, 4, 5, 5, 7, 9]))  # → 4.571428571428571
print(statistics.variance([5]))  # → StatisticsError
print(statistics.pvariance([1, 2, 3, 4, 5]))  # → 2

See also

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