Python sort() vs sorted(): What Is the Difference?

Q: What is the difference between sort() and sorted() in Python?

`sort()` changes the list in place and returns `None`, while `sorted()` returns a new sorted list and leaves the original unchanged.

Q: Is sorted() faster than sort()?

`sort()` is slightly faster and uses less memory because it does not build a second list, but both use the same algorithm (Timsort) and are O(n log n).

Q: How do I sort in descending order in Python?

Pass `reverse=True`, as in `sorted(scores, reverse=True)` or `scores.sort(reverse=True)`.

By Yogesh Sharma (LinkedIn) · Every code example is run and checked on Python 3.13 (how we test) · Last updated 21 Oct 2026

Short answer

list.sort() sorts a list in place and returns None, while sorted(iterable) leaves the original untouched and returns a new sorted list; sorted() also works on tuples, sets, strings and dictionaries.

Python has two ways to sort, and choosing the right one depends on whether you still need the original order. sort() is a method that only lists have. sorted() is a built-in function that accepts any iterable and always gives back a fresh list.

Both accept the same key and reverse arguments, so everything you learn about one transfers to the other. The sorting lesson explains the arguments in depth, and the reference pages cover list.sort() specifically.

Python

scores = [70, 95, 82]
print(sorted(scores))
print(scores)
scores.sort()
print(scores)

sort() vs sorted() comparison table

Aspect	`list.sort()`	`sorted()`
Kind	List method	Built-in function
Works on	Lists only	Any iterable: list, tuple, set, string, dict, generator
Changes the original?	Yes, in place	No
Returns	`None`	A new list
Parameters	`key=None`, `reverse=False`	`iterable`, `key=None`, `reverse=False`
Stable (keeps equal items in original order)?	Yes	Yes
Memory	No extra list is created	Creates a new list
Typical use	Sort a list you own and no longer need unsorted	Sort for display or keep the original order

When to use list.sort()

Use sort() when you own the list and the unsorted order is no longer needed.

A leaderboard that should stay sorted after each update.
Large lists where avoiding a second copy saves memory.

Remember that it returns None, so write scores.sort() on its own line and do not assign the result.

When to use sorted()

Use sorted() in all other cases.

You want to keep the original order for later.
The data is not a list: sorted("hello"), sorted(my_tuple) or sorted(my_set). Sorting a set this way is also how you print it in a predictable order.
You need a sorted result inside an expression or a function call, such as for name in sorted(names):.

Sorting a dictionary with sorted(prices) sorts its keys; use sorted(prices.items(), key=...) to sort by value.

Sorting with key and reverse

Both tools take key, a function that returns the value to compare, and reverse=True for descending order. For example key=len sorts by length and key=str.lower ignores case. Sorting is stable, so items with equal keys keep their earlier relative order, which lets you sort in several passes. A lambda is a handy short key function for records, such as key=lambda s: s["marks"].

Examples you can run

Press Run, then edit the code and run it again.

In place vs a new list

sorted() leaves prices alone, while sort() rearranges it and returns None.

In place vs a new list

prices = [30, 10, 20]
new_prices = sorted(prices)
print(new_prices)
print(prices)
result = prices.sort()
print(result)
print(prices)

Expected output[10, 20, 30]
[30, 10, 20]
None
[10, 20, 30]

sorted() works on any iterable

Strings, tuples and sets all produce a sorted list. reverse=True flips the order.

sorted() works on any iterable

print(sorted("python"))
print(sorted((3, 1, 2), reverse=True))
print(sorted({"pear", "apple", "fig"}))

Expected output['h', 'n', 'o', 'p', 't', 'y']
[3, 2, 1]
['apple', 'fig', 'pear']

Sort records by a key

The key function picks the marks, and the stable sort keeps equal marks in their original order.

Sort records by a key

students = [
    {"name": "Asha", "marks": 88},
    {"name": "Ravi", "marks": 92},
    {"name": "Meena", "marks": 88},
]
ranked = sorted(students, key=lambda s: s["marks"], reverse=True)
for s in ranked:
    print(s["name"], s["marks"])

Expected outputRavi 92
Asha 88
Meena 88

Common mistakes

Assigning the result of sort()

✗ Wrong

scores = [3, 1, 2]
scores = scores.sort()
print(scores)

None

✓ Right

scores = [3, 1, 2]
scores.sort()
print(scores)

sort() returns None. Call it on its own line, or use scores = sorted(scores).

Calling sort() on a tuple or string

✗ Wrong

point = (3, 1, 2)
point.sort()

AttributeError: 'tuple' object has no attribute 'sort'

✓ Right

point = (3, 1, 2)
print(sorted(point))

Only lists have sort(). Use sorted() to get a sorted list from any iterable.

Sorting mixed types

✗ Wrong

data = [3, "2", 1]
print(sorted(data))

TypeError: '<' not supported between instances of 'str' and 'int'

✓ Right

data = [3, "2", 1]
print(sorted(data, key=int))

Convert everything to one type first, or use a key function such as key=int.

Python sort() vs sorted(): What Is the Difference?: questions people ask

What is the difference between sort() and sorted() in Python?

sort() changes the list in place and returns None, while sorted() returns a new sorted list and leaves the original unchanged.

Is sorted() faster than sort()?

sort() is slightly faster and uses less memory because it does not build a second list, but both use the same algorithm (Timsort) and are O(n log n).

How do I sort in descending order in Python?

Pass reverse=True, as in sorted(scores, reverse=True) or scores.sort(reverse=True).

Keep learning

Step-by-step lessons:
Python Sorting Python List Methods Python Lambda Functions

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