Question

This is my second week of learning python and I got an homework assignment which I have already finished.
The thing is that one of the first stages was to take a string and delete all non letters from it (such as “,” “.” “;”, spaces, etc..)
so I took the string and each time wrote:

str1 = str.replace(',', '')
str2 = str.replace(' ', '') 
....

and so on like 5 times. My teacher says it’s fine for now. But it doesn’t look good for me.
There must be a better way instead of duplicating the code.
Can someone explain a better way of doing that?

(I tought about using an ascii function in a condition but couldn’t figure it out)

Answer 1

It’s easier to find letters than non-letters:

import string

def clean_string(input_string):
    result = ""
    for char in input_string:
        if char in string.letters: # string.letters contains a...zA...Z
            result += char
    return result

There are also fancier ways of doing this:

def clean_string2(input_string):
    return "".join([char for char in input_string if char in string.letters])