Python – Find Average of values in a List

Lists are a very versatile data structure in Python. When working with a list of numbers, it can be helpful to know how to calculate the mean of list values quickly. For example, you have a list of test scores and want to know what the average score was for the test. In this tutorial, we will look at how to get the average of a list in Python with the help of some examples.

Get average of list values in Python

You can use a combination of Python sum() and len() functions to compute the mean of a list. Alternatively, you can also use methods defined in libraries such as statistics, numpy, etc. to get the average of a list of values.

Let’s look at the above-mentioned methods with the help of examples.

1. Mean of a list using sum() and len()

To compute the mean of a list, you can use the sum() function to get the sum of the values in the list and divide that with the length of the list returned from the len() function.

# create a list
ls = [1,2,3,4]
# average of list
sum(ls) / len(ls)

Output:

2.5

We get 2.5 as the average for the list above list of values.

2. Using statistics library

You can also use the statistics standard library in Python to get the mean of a list. Pass the list as an argument to the statistics.mean() function.

import statistics

# create a list
ls = [1,2,3,4]
# average of list
statistics.mean(ls)

Output:

2.5

We get the same result as above.

For more on the statistics library, refer to its documentation.

3. Using numpy library

You can also use the numpy library to get the list average. Numpy has a number of useful functions for working with arrays in Python.

import numpy as np

# create a list
ls = [1,2,3,4]
# average of list
np.mean(ls)

Output:

2.5

We get 2.5 as the average.

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• Python – Get median of a List
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