In this tutorial, you’ll learn how to use Python to subtract two lists. You’ll learn how to do this using the popular data science library `numpy`

, for-loops, list comprehensions, and the helpful built-in `zip()`

function.

Being able to work with lists is an important skill for any Python developer, whether a beginner or an advanced Pythonista. Subtracting two lists is less intuitive than simply subtracting them. Because of this, check out the four different methods provided below to find easy ways to subtract two lists!

**The Quick Answer: Use Numpy subtract()**

Table of Contents

## Use Numpy to Subtract Two Python Lists

The popular `numpy`

library is often used for working in data science, and, as such, comes bundled with a ton of different helpful methods to manipulate numerical data. One of the primary advantages that `numpy`

provides is the `array`

object, which is very similar to the Python list object.

One of the methods that `numpy`

provides is the `subtract()`

method. The method takes two numpy `array`

s as input and provides element-wise subtractions between the two lists.

Let’s see how we can use `numpy`

and Python to subtract two lists:

# Subtract two lists with numpy import numpy as np list1 = [10, 11, 12] list2 = [1, 2, 3] array1 = np.array(list1) array2 = np.array(list2) subtracted_array = np.subtract(array1, array2) subtracted = list(subtracted_array) print(subtracted) # Returns: [9, 9, 9]

Let’s take a look at what we’ve done here:

- We loaded our two lists,
`list1`

and`list2`

and converted them into numpy arrays,`array1`

and`array2`

- We then used the
`np.subtract()`

method to subtract the two lists - Finally, since we want to return a Python list, we used the
`list()`

method

In the next section, you’ll learn how to use the `zip()`

function to find the different between two lists element-wise.

## Use Zip to Subtract Two Python Lists

The Python `zip()`

function is a built-in utility that makes working with different iterable objects incredibly easy. What the function does is iterate over different objects, element by element. Because of this, the `zip()`

function is the ideal candidate for finding the different between two lists element by element.

Let’s take a look at how we can use the Python `zip()`

function to subtract two lists:

# Subtract two lists with for loops list1 = [10, 11, 12] list2 = [1, 2, 3] subtracted = list() for item1, item2 in zip(list1, list2): item = item1 - item2 subtracted.append(item) print(subtracted) # Returns: [9, 9, 9]

Let’s take a look at what we’ve done:

- We instantiated a new, empty list called
`subtracted`

that we’ll use to hold our subtracted values - We then iterate over two items returned during each iteration of the
`zip()`

output. - We assign the difference between these two items to
`item`

and append it to our`subtracted`

list

Now, let’s take a look at how to use a for-loop to subtract two lists.

**Want to learn how to use the Python zip() function to iterate over two lists?** This tutorial teaches you exactly what the

`zip()`

function does and shows you some creative ways to use the function.## Python For Loops to Subtract Two Lists

Python for loops are incredibly helpful tools that let us repeat an action for a predetermined number of times. Because of this, we can loop over our two lists and find the different between their items.

Let’s see how we can use for loops to subtract lists:

# Subtract two lists with for loops list1 = [10, 11, 12] list2 = [1, 2, 3] subtracted = list() for i in range(len(list1)): item = list1[i] - list2[i] subtracted.append(item) print(subtracted) # Returns: [9, 9, 9]

Let’s take a look at what we’ve done with our for-loop method here:

- We created an empty list called
`subtracted`

- We then loop over the range from 0 through to the length of our first list
- We then assign the difference between each i
^{th}item of each list to our variable`item`

- This
`item`

is then appended to our list

Finally, let’s

**Want to learn more about Python for-loops?** Check out my in-depth tutorial that takes your from beginner to advanced for-loops user! Want to watch a video instead? Check out my YouTube tutorial here.

## Python List Comprehensions to Subtract Two Lists

Finally, let’s learn how we can use a list comprehension to subtract two lists. This method actually also uses the `zip()`

function to create a new list that subtracts the two lists.

Let’s take a look at how we can do this!

# Subtract two lists with zip() list1 = [10, 11, 12] list2 = [1, 2, 3] subtracted = [element1 - element2 for (element1, element2) in zip(list1, list2)] print(subtracted) # Returns: [9, 9, 9]

Let’s take a look at what we’ve done here:

- We used a list comprehension to loop over the items in the zip() object of
`list1`

and`list2`

- In this comprehension, we find the difference between the two elements

**Want to learn more about Python list comprehensions?** Check out this in-depth tutorial that covers off everything you need to know, with hands-on examples. More of a visual learner, check out my YouTube tutorial here.

## Conclusion

In this post, you learned how to use to subtract two lists. You learned how to do this using the `numpy.subract()`

method, the `zip()`

function, a Python for-loop, and a Python list comprehension. Working with lists is an important skill that doesn’t always work as you’d expect, so being prepared for different challenges you might encounter is important.

To learn more about the `numpy.subtract()`

method, check out the official documentation.