python re match exact only one occurrence (no repeat Consecutive)

Question

i want a python re to match exact one occurrence of / . indeed if occurs more / such as // or /// re shouldn't match any of them.

for example below inputs must convert:

a/b -> a b

a//b -> a//b

a/// -> a///b

Answer 1

You need (negative) lookarounds:

(?<!\/)\/(?!\/)

Demo

This regex matches a single forward slash, but only if it's not preceeded or followed by another slash.

Answer 2

You may use a regex with 2 capture groups:

r'^([^/]*)/([^/]*)$'

RegEx Demo

This regex:

• ^: Start
• ([^/]*): matches 0 or more characters that are not / and captures in group #1
• /: Match a /
• ([^/]*): matches 0 or more characters that are not / and captures in group #2
• $: End

Code:

import re
str = re.sub(r'^([^/]*)/([^/]*)$', r'\1 \2', str)