Natural Sorting in Python

If you have a list of strings containing numbers and you wanna sort in it the human sorting or natural sorting then you might like this post

For example I get something like this:

something1
something12
something17
something2
something25
something29

with the sort() method.

I know that you probably need to extract the numbers somehow and then sort the list but you have no idea how to do it in the most simple way.

The following is what you are looking for

import re

def atoi(text):
    return int(text) if text.isdigit() else text

def natural_keys(text):
    '''
    alist.sort(key=natural_keys) sorts in human order
    http://nedbatchelder.com/blog/200712/human_sorting.html
    (See Toothy's implementation in the comments)
    '''
    return [ atoi(c) for c in re.split('(\d+)', text) ]

alist=[
    "something1",
    "something12",
    "something17",
    "something2",
    "something25",
    "something29"]

alist.sort(key=natural_keys)
print(alist)

yields

['something1', 'something2', 'something12', 'something17', 'something25', 'something29']

 

 

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