Python Regx to Exclude certain letter in a alphanumeric string

Question

How to use regex to match a string that could only contain 17 alphanumerical characters and does not contains the letter 'q' 'o' and 'i'. aka, only letters and numbers but not 'q' 'o' and 'i'.

Two conditions can be done in python separately:

1. [a-z0-9]{17}
2. [^qoi]

So except specifying valid character interval or putting two conditions together using AND is there any way more elegant in python that you can actually specify the character that you want to include while excluding the ones that you do not want as such [a-z0-9&&[^qoi]] in Java

(for example, there are 10 random letters that I want to exclude, it would be very tedious to specify each interval [a-bd-eh-ow-......]

If there is no such way, I have only to accept the reality of python regex as it is.

Appreciate your help! Erik

Answer 1

you can put anything you want in square brackets. So, for example, to match any letter except q, o, and i, you can use this:

[0-9abcdefghjklmnprstuvwxyz]

You can also specify multiple ranges which might make it more obvious which characters you are skipping:

[0-9a-hj-npr-z]

There are perhaps more elegant ways to do it, but the basic concept is the same: put only the characters you want to match inside [].

Answer 2

Here are two options:

Check each condition separately

Use two regular expressions and ensure they both match. This is most like your java example.

import re
test_case = "asdFghijalkdjflkjsd"
re.match("^[A-Za-z0-9]{17}$", test_case) and re.match("^[^qoi]+$", test_case)

Explicitly list what's legal

List all legal alphanumeric characters, which should exclude q, i, and o

import re
test_case ="12345a78901234567"
re.match("^[ABCDEFGHJKLMNPRSTUVWXYZabcdefghjklmnprstuvwxyz0-9]{17}$", test_case)

Of course, this can be condensed using ranges, such as A-HJ-NPR-Z, etc.