# Python – Sort given list of strings by part the numeric part of string

Given a list of strings. The task is to sort the list by the numeric part of the string.

Examples:

Input : test_list = [“Gfg34”, “is67”, “be3st”, “f23or”, “ge9eks”]
Output : [‘be3st’, ‘ge9eks’, ‘f23or’, ‘Gfg34’, ‘is67’]
Explanation : 3 < 9 < 23 < 34 < 67, numbers extracted from strings.

Input : test_list = [“Gfg4”, “is67”, “be3st”, “f23or”, “ge9eks”]
Output : [‘be3st’, ‘Gfg4’, ‘ge9eks’, ‘f23or’, ‘is67’]
Explanation : 3 < 4 < 9 < 23 < 67, numbers extracted from strings.

Method #1 : Using sort() + re.findall()

In this, we perform the task of sorting using sort(), the explicit function is used to extract numbers using findall().

## Python3

 `# Python3 code to demonstrate working of  ` `# Sort Strings on numerical substrings ` `# Using sort() + findall() ` `import` `re ` ` `  `# helper function to perform sort ` `def` `num_sort(test_string): ` `    ``return` `list``(``map``(``int``, re.findall(r``'\d+'``, test_string)))[``0``] ` ` `  `# initializing list ` `test_list ``=` `[``"Gfg34"``, ``"is67"``, ``"be3st"``, ``"f23or"``, ``"ge9eks"``] ` ` `  `# printing original list ` `print``(``"The original list is : "` `+` `str``(test_list)) ` ` `  `# calling function ` `test_list.sort(key``=``num_sort)  ` ` `  `# printing result  ` `print``(``"Strings after numercial Sort  : "` `+` `str``(test_list)) `

Output:

The original list is : [‘Gfg34’, ‘is67’, ‘be3st’, ‘f23or’, ‘ge9eks’]
Strings after numercial Sort  : [‘be3st’, ‘ge9eks’, ‘f23or’, ‘Gfg34’, ‘is67’]

Method #2 : Using sort() + lambda + findall()

In this, we perform a similar function, but the difference being we use lambda function rather than an external function to perform the task of sorting.

## Python3

 `# Python3 code to demonstrate working of  ` `# Sort Strings on numerical substrings ` `# Using sort() + lambda + findall() ` `import` `re ` ` `  `# initializing list ` `test_list ``=` `[``"Gfg34"``, ``"is67"``, ``"be3st"``, ``"f23or"``, ``"ge9eks"``] ` ` `  `# printing original list ` `print``(``"The original list is : "` `+` `str``(test_list)) ` ` `  `# findall() getting all integers. ` `# conversion to integers using map() ` `test_list.sort(key``=``lambda` `test_string : ``list``( ` `    ``map``(``int``, re.findall(r``'\d+'``, test_string)))[``0``])  ` ` `  `# printing result  ` `print``(``"Strings after numercial Sort  : "` `+` `str``(test_list))`

Output:

The original list is : [‘Gfg34’, ‘is67’, ‘be3st’, ‘f23or’, ‘ge9eks’]
Strings after numercial Sort  : [‘be3st’, ‘ge9eks’, ‘f23or’, ‘Gfg34’, ‘is67’]

Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.

To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course.

My Personal Notes arrow_drop_up Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.

Article Tags :

Be the First to upvote.

Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.