Python sort() Function

The sort() function in Python is used to sort a list. For example:

x = [12, 43, 54, 67, 7]
x.sort()
print(x)

x = ["codes", "cracker", "dot", "com"]
x.sort()
print(x)

The output produced by this program is given below:

[7, 12, 43, 54, 67]
['codes', 'com', 'cracker', 'dot']

Unlike sorted(), the sort() function can only be used with list. Also the sort() function change the original list after the use. The function can not be used in this way:

print(x.sort())

That is, we need to sort first, then print the list.

Python sort() Function Syntax

The syntax of sort() function is:

listName.sort(reverse, key)

Both the parameters are optional. The default value of reverse is False, whereas the default value of key is None.

Note: The reverse=True is used to sort the list in descending order.

Note: The key parameter is used mostly when we need to sort the list that contains strings based on length, instead of alphabetical order. To do this, use key=len. Also we can specify the function to define the sorting criteria using key=myfun parameter.

Python sort() Function Example

Here is an example of sort() function in Python:

x = ['p', 'y', 't', 'h', 'o', 'n']
x.sort()
print(x)

The output would be:

['h', 'n', 'o', 'p', 't', 'y']

Python sort() Function with reverse Parameter

Here is an example of sort() function with reverse=True parameter:

x = ['p', 'y', 't', 'h', 'o', 'n']
x.sort(reverse=True)
print(x)

x = [12, 43, 54, 67, 7]
x.sort(reverse=True)
print(x)

x = ["codes", "cracker", "dot", "com"]
x.sort(reverse=True)
print(x)

Following is the output produced by above Python program demonstrating the sort() function with reverse parameter:

['y', 't', 'p', 'o', 'n', 'h']
[67, 54, 43, 12, 7]
['dot', 'cracker', 'com', 'codes']

Python sort() Function with key Parameter

This is the last program of this article, created to demonstrates the sort() function with key parameter in Python:

x = ["codes", "cracker", "dot", "com"]
x.sort(key=len)
print(x)

That is, the word dot and com are the smallest, containing 3 characters each. Whereas the word cracker is the largest with total of 7 characters.

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