Using a List as 1 argument in replace()

Question

Trying to solve.

I have a string from a user input. And I want to reomove all special characters from a list = [',', '.', '"', '\'', ':',]

using the replace function I´m able to remove one by one. using somethin like:

string = "a,bhc:kalaej jff!"
string.replace(",", "")

but I want to do remove all the special chr. in one go. I have tried:

unwanted_specialchr = [',', '.', '"', '\'', ':',]
string = "a,bhc:kalaej jff!"
string.replace(unwanted_specialchr, "")

Does this answer your question? [Remove specific characters from a string in Python](https://stackoverflow.com/questions/3939361/remove-specific-characters-from-a-string-in-python) — Querenker, Mar 25 '20 at 20:31

score 2 · Answer 1 · answered Mar 26 '20 at 11:53

2

figured it out:

def remove_specialchr(string):
    unwanted_specialchr = [',', '.', '"', '\'', ':',]
    for chr in string:
        if chr in  unwanted_specialchr:
            string = string.replace(chr, '')
    return string

answered Mar 26 '20 at 11:53

John_cabron

71
4

1

You can get a speedup out of this by converting `unwanted_specialchr` to a set. Replace the square brackets with curly braces. It still may not be optimal, because you have to do O(len(unwanted_specialchar)) `replace` operations, which pass over the entire string. – Arya McCarthy Mar 26 '20 at 13:51

score 1 · Answer 2 · answered Mar 25 '20 at 20:22

1

you can use re.sub:

import re

unwanted_specialchr = [',', '.', '"', '\'', ':',]
string = "a,bhc:kalaej jff!"
re.sub(f'[{"".join(unwanted_specialchr)}]', '', string)

output:

'abhckalaej jff!'

or you could use:

''.join(c for c in string if c not in unwanted_specialchr)

output:

'abhckalaej jff!'

answered Mar 25 '20 at 20:22

kederrac

16,819
6
32
55

when i try to define a code using def code(): I cant get it to return the editet string, any tips? – John_cabron Mar 26 '20 at 08:19
1

Do you want to write a function? – kederrac Mar 26 '20 at 08:22
1

you should have a return statement to return something 0_O – kederrac Mar 26 '20 at 08:24

Mandy007 · Answer 3 · 2020-03-26T14:10:11.703

1

Well i think that your solution could be better with the optimization:

def remove_specialchr(string):
    specialChr = {',', '.', '"', '\'', ':'}
    stringS = ''
    for chr in string:
        if chr not in specialChr:
            stringS += it
    return stringS

edited Mar 26 '20 at 14:10

answered Mar 26 '20 at 13:44

Mandy007

421
7
18

2

But it has to construct a new string every time you do a `+=`. Python strings are immutable. – Arya McCarthy Mar 26 '20 at 14:03

Using a List as 1 argument in replace()

3 Answers3