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This tutorial explains how to calculate the average of a list in Python. It also lists some sample codes to further clarify the concepts as the method has changed from previous Python versions.

statisticsGet the average of a list using the library

If you are using Python 3.4+, you can use the newly introduced statisticslibrary. This library contains multiple mathematical functions that can be used right out of the box. Since we want to calculate the average of a given list, we will use statistics.mean(list). listis a list of numbers. This function will return the average (mean) of the given list.

A basic example using this statistics.mean()method is shown below.

import statistics

list = [1, 2, 3, 4, 5, 6]
mean = statistics.mean(list)
print(mean)

Output:

3.5

sum()/len()Finding the average of a Python list using

Using statisticsthe library to calculate the average of a list is not the only option. The average of a list can be calculated by simply dividing the sum of the elements by the number of elements.

sum(list)Gets the sum of the given list and len(list)returns the length of the list.

data = [1, 2, 3, 4, 5, 6]
mean = sum(data) / len(data)
print(mean)

Output:

3.5

numpy.mean()Finding the average of a Python list using

We can also numpy.mean()get the average of a list in Python using the average function. The average is taken over the flattened array by default, otherwise it is taken over the specified axis.

However, before using it, you need to install NumPythe module.

The following is a sample code for using numpy.mean()to get the average of a list.

import numpy

data = [1, 2, 3, 4, 5, 6]
mean = numpy.mean(data)
print(mean)

Output:

3.5

sum()/float(len())Find the Average of a Python List in Python 2

If your Python version is 2.x, then you cannot use statisticsthe module and must use simple math to calculate the average of a given list.

For Python 2, you need to lenconvert to a floating point number to get a floating point result. The code will look like this:

data = [1, 2, 3, 4, 5, 6]
mean = sum(data) / float(len(data))
print(mean)

Output:

3.5

If you don't lenconvert to float, you won't get a floating point number but an integer, as shown below.

data = [1, 2, 3, 4, 5, 6]
mean = sum(data) / len(data)
print(mean)

Output:

3