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#
The 5 ways to find the average of a list in Python

## What is the mean of a list?

## Way 1: Using the sum() and len() function

## Way 2: Using the mean() function of NumPy

## Way 3: Using the statistics.mean() function of the statistics library

## Way 4: Using a for loop and summing the elements of the list

## Way 5: Using the reduce() function in the functools library

## Extra: Creating a custom function.

## Conclusions

Before diving into ways to find the mean of a list in Python, it's important to understand what the mean is. It is the **central numerical value of a dataset** obtained by summing all the values and dividing the result by the number of elements in the list.

The mean is an important concept in statistics and many **practical applications** in areas such as data science, engineering, and economics. By calculating the mean, we can gain a **deeper understanding** of how the data is distributed and how a population or sample behaves.

In Python, there are many different ways to find the mean of a list, from using built-in functions to creating your own custom functions. Once this is clarified, we will present **5 ways** to find it.

The `sum()`

function takes a list of numbers as an argument and **returns the sum** of all of them. On the other hand, the `len()`

**function returns** the number of **elements in a list**. Using these two functions together, we can easily calculate the average of a list in Python.

Here is an example of the code:

```
list = [2, 4, 6, 8, 10].
average = sum(list) / len(list)
print("The average of the list is:", average)
```

In this example, we create a list of numbers and then use the `sum()`

function to sum all the elements in the list. Next, we divide the result of the sum by the number of elements in the list using the `len()`

function. Finally, **print the result** as the value of the average.

info With just two built-in Python functions, you can easily calculate the average of any list of numbers you have.

`NumPy`

is a Python library used for **numeric and scientific** computation. One of its built-in functions is `mean()`

, which is used to find the mean of a set of numbers.

To do this you would have to use, for example, this code:

```
import numpy as np
list = [2, 4, 6, 6, 8, 10]
mean = np.mean(list)
print("The mean of the list is:", mean)
```

This time, we import `NumPy`

with the syntax `import numpy as np`

. Then, we create a list of numbers and use NumPy's `mean()`

function to calculate the average of the list. Finally, **print the result** as the value of the average.

info With the

`NumPy`

library, you can performcomplex numerical calculationsquicklyandefficientlyin Python.

The `statistics`

library is a Python library that includes several useful statistics functions. One of these functions is `mean()`

, which is used to calculate the mean of a list of numbers.

Here is an example of the code:

```
import statistics
list = [2, 4, 6, 6, 8, 10]
average = statistics.mean(list)
print("The mean of the list is:", mean)
```

In this case, we import the `statistics`

library with the `import statistics`

syntax. Then, we create a list of numbers and use the `mean()`

function of `statistics`

to calculate the mean of the list. Finally, **print the result** to obtain the mean value.

info The

`statistics`

library is very useful to performstatisticalandmathematicalcalculations in Python in a simple way.

Another way to calculate the average of a list in Python is to use a `for`

loop to sum all the elements in the list and then divide that sum by the **amount of elements** in the list.

An example of code you can try:

```
list = [2, 4, 6, 8, 10].
sum = 0
for num in list:
sum += num
average = sum / len(list)
print("The average of the list is:", average)
```

Here we create a list of numbers and use a `for`

loop to sum all the elements in the list. Then, we divide that sum by the number of items in the list to get the average. Finally, we **print the result** as the value of the mean.

info This way of calculating the mean is a bit

more complex than the previous ones, but it is very useful when you don't have access toexternal librariesor just prefer to use simpler, more straightforward Python code.

The `reduce()`

function of the *functools* library allows us to apply an operation to **all elements** of a list in **cumulative** fashion. To calculate the average of a list using `reduce()`

, we first need to import the *functools* library and the `reduce()`

function. Then, we use `reduce()`

to sum all the elements in the list and divide that sum by the number of elements in the list.

Here is a code example:

```
from functools import reduce
list = [2, 4, 6, 8, 10].
sum = reduce(lambda x, y: x + y, list)
average = sum / len(list)
print("The average of the list is:", average)
```

In this example, we import the *functools* library and the `reduce()`

function. Then, we create a list of numbers and use `reduce()`

to sum all the elements in the list. Finally, we **divided that sum** by the **amount of elements** in the list to get the average.

info This way of calculating the average is very useful when you are working with

large amounts of dataand need a quick and efficient solution.

Just as you read it, at the end we present you not only 5 ways to find the average of a list in Phyton, but **six**. This option can be useful if you need to perform **additional calculations** or if you want to **customize the output of your function**.

If you have the need to calculate the average of a list on **multiple occasions** in your code, it can be useful to create a custom function to make it easier and faster. A function is a block of code that performs a specific task and can be called at any time.

Here is an example code:

```
def calculate_average(list):
sum = 0
for num in list:
sum += num
average = sum / len(list)
return average
list = [2, 4, 6, 8, 10].
average = calculate_average(list)
print("The average of the list is:", average)
```

In this example, we create a custom function called `calculate_average`

that takes a list as **parameter**. Inside the function, we create a variable called `sum`

that starts at zero and use a **for** loop to iterate over each number in the list and sum them. Then, we divide the total sum by the **length of the list** to get the average and return it as the result.

To use this function, we simply pass our list as an argument and store the result in a variable called `average`

.

success Done! You now know six different ways to find the average of a list in Python. You can now take advantage of them in your tasks and/or projects.

We hope you found this tutorial helpful. Calculating the mean of a list is a common task in Python data analysis and programming, and these five options will allow you to do it **quickly and efficiently**. Also, remember that you can always customize your code and create your own function to suit your **specific needs**.

Don't be discouraged if you are not yet comfortable with Python. Programming can be challenging, but it can also be exciting and quite rewarding. With practice and perseverance, you will be able to master any Python task that comes your way.