Python class attribute repeating value

Question

I would like to know why this check variable repeating the previous value as && instead of entering the new text Bob. How to implement the below code so that Check variable will not repeat the previous value?
I have tried to add check=check.replace(check,"") to make the variable Check blank. However it still taking the old value as &&. How to fix this?

class Game:
    alphabet=['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z','a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']

    def __init__(self):
        self.char_list=''

    def check_char(self,txt):
        for i in txt:
            if i not in self.alphabet:
                self.char_list+=i
        return self.char_list

game=Game()
limit=0
while not limit>4:
    text = list(input("Type your message:n").lower())
    print(text)
    check=game.check_char(text)
    print(check)
    limit+=1
    continue
    if limit==5:
        break
output:
Type your message:
hello&&
['h', 'e', 'l', 'l', 'o', '&', '&']
&&`enter code here`
Type your message:
bob
['b', 'o', 'b']
&&
Type your message:

Asked By: Mithel

||

Source

Answer 1

Each iteration of your while loop is using the same instance of Game. The instance variable char_list is cumulative. You probably don’t want an instance variable. Use a function-local variable instead or even a one-liner that doesn’t require an explicit variable declaration.

from string import ascii_lowercase as ALPHABET

class Game:
    def __init__(self):
        pass
    def check_char(self, txt):
        return ''.join(c for c in txt if c not in ALPHABET)

game = Game()

for _ in range(4):
    msg = input('Type your message: ').lower()
    print(game.check_char(msg))

Answered By: DarkKnight

Answer 2

class Game:
        alphabet=['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z','a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
 
        def check_char(self,txt):
            char_list=''
            for i in txt:
                if i not in self.alphabet:
                    char_list+=i
            return char_list

Answered By: TheEngineerProgrammer

Python class attribute repeating value

Question:

Answers: