Remove all characters from string except alphabets in Python

Understanding String Filtering

Filtering a string means removing all non-alphabetic characters from it.

We will explore three different methods to achieve this in Python.

Method 1: Using a Loop

This method iterates through the string and keeps only alphabetic characters.

def remove_non_alpha(s):
    result = "".join(c for c in s if c.isalpha())
    return result

# Example usage
string = "H3ll0 W@rld!"
print("Filtered String:", remove_non_alpha(string))
            

Method 2: Using Recursion

This method filters the string recursively.

def filter_recursive(s):
    if not s:
        return ""
    return (s[0] if s[0].isalpha() else "") + filter_recursive(s[1:])

# Example usage
string = "C0d!ng123"
print("Filtered String:", filter_recursive(string))
            

Method 3: Using Regular Expressions

This method uses regex to replace all non-alphabetic characters.

import re

def remove_with_regex(s):
    return re.sub(r'[^a-zA-Z]', '', s)

# Example usage
string = "P@r0gr@mm1ng"
print("Filtered String:", remove_with_regex(string))