Python statistics.pvariance() Function

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The Python statistics.pvariance function returns the population variance of data, a non-empty sequence or iterable of real-valued numbers. The mean is the measure of the variability (spread or dispersion) of the data.

In this function, if the optional argument 'mu' is given, it should be the population mean of the data. It can also be used to compute the second argument around a point that is not the mean.

We use this function to calculate the variance for the entire population. This function throws a StatisticsError if the data is empty.

Syntax

Following is the basic syntax statistics.pvariance() function −

statistics.pvariance(data, mu=None)

Parameters

Here, the data values can be used as any sequence, list or iterator and mu is an optional argument that varies the entire population.

Return Value

This function returns a non-empty sequence or iterable of real valued numbers.

Example 1

Now, we are calculating the population variance from the given dataset using statistics.pvariance() function.

import statistics
x = [3.0, 5.5, 7.9, 9.01, 1.23, 3.24]
variance = statistics.pvariance(x)
print(f"The Population Variance is: {variance:.4f}")

Output

This produces the following result −

The population variance is: 7.6747

Example 2

In the below example, we are calculating the optional second argument 'mu' to avoid recalculations using statistics.pvariance() function.

import statistics
x = [3.2, 6.5, 0.0, 1.25, 2.34, 0.13]
mu = statistics.mean(x)
variance = statistics.pvariance(x, mu)
print(f"The Population Variance is: {variance:.4f}")

Output

The output is obtained as follows −

The Population Variance is: 4.9215

Example 3

Let us write a simple Python program with decimals using statistics.pvariance function.

import statistics
from decimal import Decimal as D
x = [D("34.56"), D("45.23"), D("12.12"), D("11.31")]
variance = statistics.pvariance(x)
print(f"The Population Variance is: {variance:.4f}")

Output

We will get the output as follows −

The Population Variance is: 212.8412

Example 4

In Population Variance, we are writing a code with fractions using statistics.pvariance() function.

import statistics
from fractions import Fraction as F
x = [F(2, 5), F(6, 7), F(9, 4), F(2, 1)]
variance = statistics.pvariance(x)
variance_float = float(variance)
print(f"The Population Variance is: {variance_float:.4f}")

Output

This will produce the following result −

The Population Variance is: 0.5938