delete characters in string with python

Question

I would like to delete from a string all the characters from a list.

For example:

to_delete = ["w","r"]
word = "word"

word.replace(to_delete,'')

>> od

What is the best/fast solution to do it? Is it possible without loops?

Thanks in advance

"without loops" at all? At some level, you're iterating every character of the string — OneCricketeer, Dec 03 '18 at 14:34

score 2 · Answer 1 · answered Dec 03 '18 at 14:32

2

Use str.translate.

>>> word = "word"
>>> to_delete = ["w","r"]
>>> 
>>> trans = str.maketrans(dict.fromkeys(to_delete))
>>> word.translate(trans)
'od'

answered Dec 03 '18 at 14:32

timgeb

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Maximilian Burszley · Accepted Answer · 2018-12-03T14:56:29.317

2

I'd suggest regex:

import re

word = "word"
to_delete = ['w', 'r']

re.sub(f"[{''.join({re.escape(i) for i in to_delete})}]", '', word)

This will join your characters to replace into a regex set pattern for replacement, takes the word as input, and replaces those characters with empty strings.

edited Dec 03 '18 at 14:56

answered Dec 03 '18 at 14:35

Maximilian Burszley

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4
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I would just start with `to_delete = "wr"` and save the join step. – OneCricketeer Dec 03 '18 at 14:41
1

regex is a fun approach, but take care to only try this if the to_delete characters are "nice". If one of them has a special meaning in the context of a regex pattern, things may go wrong. For example, if to_delete is `['w', ']']`, your code will output `word` instead of the desired `ord`. – Kevin Dec 03 '18 at 14:43
@cricket_007 I was working with the OP's starting set – Maximilian Burszley Dec 03 '18 at 14:44
@Kevin Mostly familiar with .net, wasn't sure if there was a `Regex.Escape`-type method – Maximilian Burszley Dec 03 '18 at 14:45
@TheIncorrigible1, I like the idea of escaping. I think `re.escape` might do the trick. – Kevin Dec 03 '18 at 14:49
@Kevin Found the doc and updated the answer (even though the Q is closed) – Maximilian Burszley Dec 03 '18 at 14:51

delete characters in string with python

2 Answers2