使用正则表达式从字符串中删除字符

Question

There is a practice problem in the book im reading which asks you to create a function which defaults to removing white space from a string and if you give it a character as an argument it removes that character from the string (basically recreating the strip method). I have written something which I think should work, it can remove the white space but wont remove the character argument i put in, it just doesn't print to the console.

import re 

def re_move(text,chars=0):
    string_regexx = re.compile(r"\S+")
    chars_regexx = re.compile(r"^chars") 

    if chars == 0:
        f1 = string_regexx.findall(text)
        return "".join(f1)


    elif chars != 0:
        e1 = chars_regexx.findall(text)
        return " ".join(e1)

#should remove white space
print(re_move("tokyo is in japan"))

#should remove all e values
print(re_move("hello there","e"))

There is no error but the expected string with the removed e values is not output onto the console and I dont know why?

Answer 1

The easiest way to remove white space from a string, text is:

text = re.sub(r'\s+', '', text)

Likewise, to remove, for example, characters 'a' and 'b':

text = re.sub('[ab]+', '', text)

To test for an optional parameter, chars , it is usual to specify a default value of None :

import re

def re_move(text, chars=None):
    text = re.sub(r'\s+', '', text)
    if chars:
        text = re.sub(f'[{chars}]+', '', text)
    return text

print(re_move('abc def ghi ', chars='beh'))

Prints:

acdfgi