How to check if a string has at least one letter and one number

Question

I am trying to build a logic where I need to write code in such a way that my string should contain

alphabet and number both. If not print sting does not contain letter else number or both

My code:

stg = 'abc123'

stg.isalnum()

Output :

True

Even if my string does not contain number then also gives me : True. That I don't want it

My string should contain at least one letter and number

Does this answer your question? [Regex pattern to match at least 1 number and 1 character in a string](https://stackoverflow.com/questions/7684815/regex-pattern-to-match-at-least-1-number-and-1-character-in-a-string) — Imtinan Azhar, Oct 13 '22 at 10:54
I think using regex for a simple text manipulation task like this is a bit overkill, @ImtinanAzhar — Salman Farsi, Oct 13 '22 at 10:55
I guess `if any(c.isalnum() for c in stg) and any(c.isalpha() for c in stg):` does the job. — Salman Farsi, Oct 13 '22 at 10:59
@SalmanFarsi You mean `isdigit()` where you have `isalnum()`. — khelwood, Oct 13 '22 at 11:43

Lucas M. Uriarte · Accepted Answer · 2022-10-13T11:15:59.783

2

you could use

import re
bool(re.match("\d+[a-zA-Z]+|[a-zA-Z]+\d+", stg))

edited Oct 13 '22 at 11:15

answered Oct 13 '22 at 11:04

Lucas M. Uriarte

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Casting Spell · Answer 2 · 2022-10-13T15:17:28.403

0

This will do the work

def hasCharNum(inputString):
    return any(char.isdigit() for char in inputString) and any(char.isalpha() for char in inputString)

hasCharNum("Python3")

True

edited Oct 13 '22 at 15:17

answered Oct 13 '22 at 10:57

Casting Spell

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What about `3Python`? – luk2302 Oct 13 '22 at 10:58
1

This does not work for case where the number is first – jeekiii Oct 13 '22 at 11:01
Still incorrect. The other answer works. You should probably delete your answer or edit it to say it does not work. – jeekiii Oct 13 '22 at 11:07
1

The regex from the comment now expects a number in the end regardless of a number being at the start already. – luk2302 Oct 13 '22 at 11:10

How to check if a string has at least one letter and one number

2 Answers2