How to remove all characters within a string after a non-alphanumerical character

Question

I want to remove all the character after a non-alphanumerical character ('_') within a string. For example:

Petr_;Y -> Petr 
ČEZ_^(České_energetické_závody) -> ČEZ

I tried:

''.join(c for c in mystring if c.isalnum())

But this way I'm stripping off only alphanumerical characters itself.

Help would be appreciated.

An efficient way is you can use re module in python to achieve this, >>> from re import split >>> s1 = "ČEZ_^(České_energetické_závody)" >>> split('_', s1)[0] 'ČEZ' — Dhinesh Sunder Ganapathi, Jun 28 '21 at 12:26

score 3 · Accepted Answer · answered Jun 28 '21 at 12:04

3

You may want to use the .split() method on strings.

new_string = your_string.split('_',1)[0]

This way you keep only what's before the fisrt '_'.

answered Jun 28 '21 at 12:04

zanga

score 1 · Answer 2 · answered Jun 28 '21 at 12:09

1

Searching the index of first occurrence of "_" will do:

s1 = "Petr_;Y"  
s2 = "ČEZ_^(České_energetické_závody)"

s11 = s1[:s1.index("_")]
s22 = s2[:s2.index("_")]

answered Jun 28 '21 at 12:09

zwitsch

2

Keep in mind this will produce an `ValueError` if there is no `_` in the input string. – chepner Jun 28 '21 at 12:11
I agree with that, but since "_" seemed to be given here, I preferred to focus on detecting it. – zwitsch Jun 28 '21 at 12:14

2 Answers2