docs: def open_database(self):
          """
          Opens the sqlite database.
  
          """
          if not self.con:
              try:
                  self.con = psycopg2.connect(host=self.host,
                      database=self.dbname, user=self.user,
                      password=self.password, port=self.port)
              except psycopg2.Error as e:
                  print("Error while opening database:")
                  print(e.pgerror)