How to use isintance with condition?

[Azdaghost]

Hello! I am trying to make my own language and I came across a problem.

I want it to check the type of data the user inputted, but the thing is that its a string.
And as I was looking for sources, I thought of eval() but they said they could hack into my computer.

I also resided to isinstance, but it will always result in True ONLY if I'm checking if its a string.
So how can I get the type of a variable in a string type while not using eval()?

Full Code:

class Token:
    def __init__(self, type, value):
        self.type = type
        self.value = value

class Reader:
    def __init__(self, text):
        self.text = text
    def get_tokens(self):
        save = ''
        tokens = []
        for index in range(len(self.text)):
            if self.text[index] != ',' and self.text[index] != ' ':
                save += self.text[index]
            else:
                print(self.text[index])
                if save == '+':
                    tokens.append(Token('TT_SYMBOL_PLUS', '+'))
                elif save == '-':
                    tokens.append(Token('TT_SYMBOL_MINUS', '-'))
                elif save == '*' or save == '++':
                    tokens.append(Token('TT_SYMBOL_MULTI', save))
                elif save == '/' or save == '--':
                    tokens.append(Token('TT_SYMBOL_DIVIDE', save))
                elif save == '^' or save == '**' or save == '+++':
                    tokens.append(Token('TT_MATH_EXPONENT', save))
                elif save == '=':
                    tokens.append(Token('TT_SYMBOL_EQUALSIGN', '='))
                else:
                    tokens.append(Token('TT_SPECIAL_UNKNOWN', save))
                save = ''
        return tokens

class Decoder:
    def __init__(self, tokens):
        self.tokens = tokens
    def decode(self):
        updatedtokens = []
        for token in self.tokens:
            updatedtokens += [token.type, token.value]
        return updatedtokens
        
while True:
    cmd = input()
    print(Decoder(Reader(cmd).get_tokens()).decode())

[deanhystad]

What types can it be?

[Gribouillis]

You are trying to create a lexer in Python. A simple way to do that is to use regular expressions to recognize lexical tokens in the input streams.

If you are ready to start with an external module that already tackles this problem, you could start with PLY which comes with support for writing lexical analysers.

[buran]

I also resided to isinstance, but it will always result in True ONLY if I'm checking if its a string.

Just to mention that this is not surprising if you check what has been returned from input() - it is always string