def better_calc(self, action):
    message = action["payload"]
    player = message["player"]
    request_source = action["source"]

    command = message["parsed_command"]

    def parse_input(raw_input: str) -> list:
        pattern = re.compile(r"([+/*-])")
        input_with_spaces = re.sub(pattern, r" \1 ", raw_input)

        input_list = input_with_spaces.split()

        def is_floatable(n):
            n = n.replace(".", "", 1)
            return n.isnumeric()

        converted_list = [float(value) if is_floatable(value) else value for value in input_list]

        for value in converted_list:
            if not (isinstance(value, float) or re.search(pattern, value)):
                raise ValueError

        return converted_list

    if command['payload'] is not None:
        input_string = command["payload"]
    else:
        return

    calculation_map = {
        "*": (lambda a, b: a * b),
        "/": (lambda a, b: a / b),
        "+": (lambda a, b: a + b),
        "-": (lambda a, b: a - b),
    }

    parsed_list = parse_input(input_string)

    if len(parsed_list) % 2 == 0:
        return

    for operator, func in calculation_map.items():
        while operator in parsed_list:
            op_index = parsed_list.index(operator)

            a = parsed_list[op_index - 1]
            b = parsed_list[op_index + 1]

            if operator == "/" and b == 0:
                print("Better calc: divide by zero error.")
                return
            new_value = func(a, b)

            parsed_list[op_index - 1] = new_value
            del parsed_list[op_index:op_index + 2]

    reply_string = f"{player['username'].capitalize()}, here is the result: {parsed_list[0]}"