How to Convert List of Tuples to List of Lists in Python?

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If you’re in a hurry, here’s the short answer:

Use the list comprehension statement [list(x) for x in tuples] to convert each tuple in tuples to a list. This also works for a list of tuples with a varying number of elements.

How to Convert List of Lists to List of Tuples in Python? (And Back)

But there’s more to it, and studying the three main methods to achieve the same goal will make you a better coder. So keep reading! 👓

Method 1: List Comprehension + list()

Problem: How to convert a list of tuples into a list of lists?

Example: You’ve got a list of tuples [(1, 2), (3, 4), (5, 6)] and you want to convert it into a list of lists [[1, 2], [3, 4], [5, 6]].

Solution: There are different solutions to convert a list of tuples to a list of lists. The recommended way is to use list comprehension in its most basic form:

tuples = [(1, 2), (3, 4), (5, 6)]
lists = [list(x) for x in tuples]
# [[1, 2], [3, 4], [5, 6]]

Try It Yourself:

This approach is simple and effective. List comprehension defines how to convert each value (x in the example) to a new list element.

You use the constructor list(x) to create a new list from the tuple x.

Python list() — A Simple Guide

If you have three list elements per tuple, you can use the same approach with the conversion:

tuples = [(1, 2, 1), (3, 4, 3), (5, 6, 5)]
lists = [list(x) for x in tuples]

You can see the execution flow in the following interactive visualization (just click the “Next” button to see what’s happening in the code):

And if you have a varying number of list elements per tuple, this approach still works beautifully:

tuples = [(1,), (3, 3), (5, 6, 5)]
lists = [list(x) for x in tuples]
# [[1], [3, 3], [5, 6, 5]]

You see that an approach with list comprehension is the best way to convert a list of tuples to a list of lists. But are there any alternatives?

Method 2: Map Function + list()

An alternative is to use the map function that applies a specified function on each element of an iterable.

💡 Side note: Guido van Rossum, the creator of Python, didn’t like the map() function as it’s less readable (and less efficient) than the list comprehension version (method 1 in this tutorial). Feel free to read a detailed discussion on how exactly he argued in my blog article.

So, without further ado, here’s how you can convert a list of tuples into a list of lists using the map() function:

tuples = [(1,), (2, 3, 4), (5, 6, 7, 8)]
lists = list(map(list, tuples))
# [[1], [2, 3, 4], [5, 6, 7, 8]]

Try it yourself:

The first argument of the map() function is the list function name.

This list() function converts each element on the given iterable tuples (the second argument) into a list.

The result of the map() function is an iterable, so you need to convert it to a list before printing it to the shell because the default string representation of an iterable is not human-readable.

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Method 3: Use Asterisk and List Comprehension

A variant of the recommended way to convert a list of tuples to a list of lists is using list comprehension in combination with the unpacking asterisk operator * like so: [[*x] for x in tuples].

Here’s an example:

tuples = [(1,), (3, 3), (5, 6, 5)]
lists = [[*x] for x in tuples]

# [[1], [3, 3], [5, 6, 5]]

The unpacking operator [*x] takes all tuple elements from x and “unpacks” them in the outer list container [...]. For example, the expression [*(5, 6, 5)] yields the list [5, 6, 5].

Where to Go From Here?

Enough theory. Let’s get some practice!

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