Python:我可以访问在class bar中创建的类foo中的类实例吗？

Question

我有一个如下的类：

class Hand():
    def __init__(self, hand_a, play_deck, split_count, name): # hand_a for hand actual
        self.hand_a = hand_a  # the actual hand when instance created
        self.play_deck = play_deck  #  need to move this to deck class
        self.split_count = split_count
        self.name = name

在另一个类中，我创建了Hand的一个实例：

class DECK():
    def __init__(self):
        pass

    def deal(self, play_deck):
        dhand = {}
        phand = {}
        for i in range (2):
            play_deck, phand[i] = pick_item(play_deck)
            play_deck, dhand[i] = pick_item(play_deck)

        # creat instance of Hand for player's starting hand
        self.start_hand = Hand(phand, play_deck, 0, "Player 1")

在第三个类中，我尝试访问我的第一个Hand实例，名为'start_hand'：

class Game():
    def __init__(self):
        pass

    def play_game(self):
        self.deck = DECK()
        self.deck.deal(play_deck)
        print "dhand = %r" % start_hand.hand_a

但我得到以下错误：

   print "dhand = %r" % start_hand.hand_a
NameError: global name 'start_hand' is not defined

我也尝试过：

print "dhand = %r" % self.start_hand.hand_a

但我得到以下错误：

    print "dhand = %r" % self.start_hand.hand_a
AttributeError: Game instance has no attribute 'start_hand'

我是否必须以其他方式创建类实例，或者必须以不同方式访问它，或者两者都有？还是我太离谱了，我应该从头开始？

Answer 1

您的对象是deck start_hand的成员。

print "dhand = %r" % self.deck.start_hand.hand_a

Answer 2

可以，您可以访问该属性。你想要的

self.deck.start_hand.hand_a
# ^ deck object you just created
#         ^Hand object created by the deck constructor/initiator (DECK.__init__)
#                    ^ starting hand attribute of hand object.

Answer 3

你为什么不试试这个呢？

def deal(self, play_deck):
  ...
  return start_hand

否则，start_hand是DECK对象的成员，因此您必须：

self.deck.start_hand

才能访问它。