使用itertools.product在Python中从for循环输出创建列表

Question

我的目标是用Python创建一副扑克牌的列表。我正在使用itertools.product。下面的代码可以生成正确的列表，但它只能在循环内部工作。

我该如何在循环外部存储和使用这个列表呢？

在循环内部打印列表：

#CARDS#
import itertools
rank = ["2", "3", "4", "5", "6", "7", "8", "9", "T", "J", "Q", "K", "A"]
suit = ["h", "d", "s", "c"]

for card in itertools.product(rank, suit):
    card_deck = card[0] + card[1]
    print card_deck

输出：

2h 2d 2s 2c 3h 3d 3s 3c 4h 4d 4s 4c 5h 5d 5s 5c 6h 6d 6s 6c 7h 7d 7s 7c 8h 8d 8s 8c 9h 9d 9s 9c Th Td Ts Tc Jh Jd Js Jc Qh Qd Qs Qc Kh Kd Ks Kc Ah Ad As Ac

在循环外部打印列表：

for card in itertools.product(rank, suit):
    card_deck = card[0] + card[1]
print card_deck

输出：

Ac

Answer 1

问题是，当你完成循环后，card_deck 里仍然保留着最后一个值。如果你想要所有的值，就需要把它们存储到某个地方……也许可以用一个列表：

card_deck = []
for card in itertools.product(rank, suit):
    card_deck.append(card[0] + card[1])

print card_deck

而且这看起来非常适合用列表推导式来实现：

card_deck = [card[0] + card[1] for card in itertools.product(rank, suit)]