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

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.

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]
print(lists)
# [[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.

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]
print(lists)

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]
print(lists)
# [[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))
print(lists)
# [[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.

Related Articles

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]

print(lists)
# [[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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