If you’re in a hurry, here’s the most Pythonic way to convert a nested list to a nested tuple:
Here’s a graphic on how to convert back and forth between nested list and nested tuples:
But there’s more to it! Studying the different methods to achieve the same goal will make you a better coder. 🧑💻
So keep reading!
Method 1: Tuple Comprehension + tuple()
Here’s a concrete example:
lists = [[1, 2], [3, 4], [5, 6]] tuples = tuple(tuple(x) for x in lists) print(tuples) # ((1, 2), (3, 4), (5, 6))
Try It Yourself:
This approach is simple and effective. The generator expression defines how to convert each inner list (
x in the example) to a new tuple element.
You use the constructor
tuple(x) to create a new tuple from the list
Example Three Elements per Tuple
If you have three elements per list, you can use the same approach with the conversion:
lists = [[1, 2, 1], [3, 4, 3], [5, 6, 5]] tuples = tuple(tuple(x) for x in lists) print(tuples) # ((1, 2, 1), (3, 4, 3), (5, 6, 5))
You can see the execution flow in the following interactive visualization (just click the “Next” button to see what’s happening in the code):
Example Varying Number of List Elements
And if you have a varying number of elements per list, this approach still works beautifully:
lists = [, [2, 4, 3], [6, 5]] tuples = tuple(tuple(x) for x in lists) print(tuples) # ((1,), (2, 4, 3), (6, 5))
You see that an approach with generator expression is the best way to convert a list of lists to a tuple of tuples.
But are there any alternatives? Let’s have a look at a completely different approach to solve this problem:
Method 2: Map Function + list()
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 generator expression version (Method 1 in this tutorial). You can read about a detailed discussion on how exactly he argued on my blog article.
So, without further ado, here’s how you can convert a list of lists into a tuple of tuples using the
lists = [, [2, 4, 3], [6, 5]] tuples = tuple(map(tuple, lists)) print(tuples) # ((1,), (2, 4, 3), (6, 5))
Try it yourself:
Video tutorial on the
The first argument of the
map() function is the
tuple function name.
The result of the
map() function is an iterable too, so you need to convert it to a tuple before printing it to the shell because the default string representation of an iterable is not human-readable.
Method 3: Simple For Loop with append() and tuple()
To convert a list of lists to a tuple of tuples, first initialize an empty “outer” list and store it in a variable.
Next, append each result to the outer list variable using the
list.append() builtin method in the loop body.
Finally, convert the list of tuples to a list tuple of tuples using the
The following example does exactly that:
lists = [, [2, 4, 3], [6, 5]] tmp =  for t in lists: tmp.append(tuple(t)) tuples = tuple(tmp) print(tuples) # ((1,), (2, 4, 3), (6, 5))
Related Video Tutorial
Related Conversion Articles
- How to Convert a List of Lists to a List of Tuples
- How to Convert a List of Lists to a Pandas Dataframe
- How to Convert a List of Lists to a NumPy Array
- How to Convert a List of Lists to a Dictionary in Python
- How to Convert a Tuple of Tuples to a List of Lists in Python
Where to Go From Here?
Enough theory. Let’s get some practice!
Coders get paid six figures and more because they can solve problems more effectively using machine intelligence and automation.
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You build high-value coding skills by working on practical coding projects!
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🚀 If your answer is YES!, consider becoming a Python freelance developer! It’s the best way of approaching the task of improving your Python skills—even if you are a complete beginner.
If you just want to learn about the freelancing opportunity, feel free to watch my free webinar “How to Build Your High-Income Skill Python” and learn how I grew my coding business online and how you can, too—from the comfort of your own home.
While working as a researcher in distributed systems, Dr. Christian Mayer found his love for teaching computer science students.
To help students reach higher levels of Python success, he founded the programming education website Finxter.com. He’s author of the popular programming book Python One-Liners (NoStarch 2020), coauthor of the Coffee Break Python series of self-published books, computer science enthusiast, freelancer, and owner of one of the top 10 largest Python blogs worldwide.
His passions are writing, reading, and coding. But his greatest passion is to serve aspiring coders through Finxter and help them to boost their skills. You can join his free email academy here.