database

import json
class Database:

    def __init__(self, filename):
        self.__lista = []
        self.__filename = filename

        try:
            f = open(self.__filename, "r")
            self.__lista = json.load(f)
        except:
            f = open(self.__filename, "w")
            f.close()

    def add(self, c):
        self.__lista.append(c)

    def save(self):
        with open(self.__filename, 'w') as json_file:
            json.dump(self.__lista, json_file, indent=2)

ERRORE : raise TypeError(f'Object of type {o.__class__.__name__} '
        TypeError: Object of type Cocktail is not JSON serializable

(cocktail è un dizionario)