Running error in python when trying to filter chars from string-CodePudding

I'm trying to implement a function that gets an input string (for example: input = 1234@Hello) and the function will return only the chars (in the example: return Hello)

So I created a function that get a variable which is the input, converting one by one to char and checking if the char is a letter. if so, the function will add the letter to final string.

When I tried to run the script, and gave it input, I got the following error: [1234HI

Traceback (most recent call last):line 6, in select_only_chars char = chr() TypeError: chr() takes exactly one argument (0 given)]

key = input()

def select_only_chars(user_input):
    full_string = user_input
    char = chr()
    final_string = ''
    for char in full_string:
        if ('a' <= char <= 'z') or ('A' <= char <= 'Z'):
            final_string  = char
    return final_string

print(select_only_chars(key))

CodePudding user response：

Alternative solution

import string

def select_only_chars(user_input):
    full_string = user_input
    all_letters = string.ascii_lowercase   string.ascii_uppercase
    final_string = ''
    for char in full_string:
        if char in all_letters:
            final_string  = char
    return final_string

key = "1234@Hello"
print(select_only_chars(key))

CodePudding user response：

Credit to @Jhonny Mopp Deleting the char = chr() variable fixed the whole code.