Sorting an array of strings having alphanumeric values (Python3)

Question

I have an array having values as following : ['1.hello', '10.hel', '12B.hepl', '9.hell', '12A.help', '2.helo']

I want these sorted as : ['1.hello', '2.helo', '9.hell', '10.hel', '12A.help', '12B.hepl']

Any regex solution would also be preferred. Anything after the . is not to be considered for sorting the array

If you install the `natsort` library, this is a single function call. — cs95, Dec 20 '20 at 06:41

adir abargil · Accepted Answer · 2020-12-20T07:35:47.497

1

Just fint the first number sequence and cast it to int:

import re
def get_sorting(s):
    s = re.findall(r'^\d+[A-Z]\.', s)[0].rstrip('.')
    num = int(s[:-1])
    return num, s[-1]

arr = sorted(arr, key = get_sorting)

update

As suggested By @ Raj006 in comments if you want it to support many letters after number use below function instead :

def get_sorting(s):
    a = re.match('(\d+)([A-Z]*)\.', s) 
    number = int(a.group(1)) 
    text = a.group(2)
    return number,text

edited Dec 20 '20 at 07:35

answered Dec 20 '20 at 06:40

adir abargil

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Change the regular expression to look from the beginning of the string `r'^\d+[A-Z]\.'` to be more explicit. Otherwise, the solution looks good. – Raj006 Dec 20 '20 at 06:59
x is not defined in line 3 – Ishaan Kanwar Dec 20 '20 at 07:06
giving an error list index out of range when replaced x with s – Ishaan Kanwar Dec 20 '20 at 07:17
`a = re.match('(\d+)([A-Z]*)\.', s)` `number = int(a.group(1))` `text = a.group(2)` `return number, text` This will give you a complete solution, and of course `natsort` library will also do that. – Raj006 Dec 20 '20 at 07:29
Let me check it , are you sure you are testing the function for the given input? – adir abargil Dec 20 '20 at 07:32

Sorting an array of strings having alphanumeric values (Python3)

1 Answers1