# Python List sort() method

• Difficulty Level : Easy
• Last Updated : 16 Aug, 2022

Python list sort() function can be used to sort a List in ascending, descending, or user-defined order. In each case, the time complexity is O(nlogn) in Python.

### Syntax of sort() function

Syntax: List_name.sort(reverse=True/False, key=myFunc)

Parameter:

• reverse: (Optional), reverse=True will sort the list descending. Default is reverse=False
• key Optional. A function to specify the sorting criteria(s)

### Example 1: Sort the List of numbers in Ascending Order

The sort() method by default sort element in ascending order as we can see below example:

## Python3

 `# Python program to demonestrate to``# sorting numbers in Ascending Order`` ` `numbers ``=` `[``1``, ``3``, ``4``, ``2``]``# Sorting list of Integers in ascending``numbers.sort()``print``(numbers)`

Output:

`[1, 2, 3, 4]`

### Example 2: Sort the List of alphabets in Ascending Order

The sort() method sorts the list in order from A-Z, to a-z in the alphabet.

## Python3

 `# Sorting List in Descending Order ``# Creating List``strs ``=` `[``"geeks"``, ``"code"``, ``"ide"``, ``"practice"``]`` ` `# Sorting list of Integers in ascending``# using sort() methods``strs.sort()``print``(strs)`

Output:

`['code', 'geeks', 'ide', 'practice']`

### Example 3: Sort the List in Descending Order

Here, we are sorting the list of numbers in Descending order, the same will be for alphabets(Z-A, z-a).

## Python3

 `# Python program to demonestrate to``# sorting numbers in descending Order``# Creating List of Numbers``numbers ``=` `[``1``, ``3``, ``4``, ``2``]`` ` `# Sorting list of Integers in descending``numbers.sort(reverse ``=` `True``)`` ` `print``(numbers)`

Output:

`[4, 3, 2, 1]`

### Example 4: Sorting using User-defined Order

In this example, we are sorting elements using the function based by passing the function to the key parameter of the sort() function.

## Python3

 `# function to return the second element of the``# two elements passed as the parameter``def` `sortSecond(val):``    ``return` `val[``1``]`` ` `# list1 to demonstrate the use of sorting``# using  second key``list1 ``=` `[(``1``, ``2``), (``3``, ``3``), (``1``, ``1``)]`` ` `# sorts the array in ascending according to``# second element``list1.sort(key``=``sortSecond)``print``(list1)`` ` `# sorts the array in descending according to``# second element``list1.sort(key``=``sortSecond, reverse``=``True``)``print``(list1)`

Output:

```[(1, 1), (1, 2), (3, 3)]
[(3, 3), (1, 2), (1, 1)]```

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