我遇到的问题是变量没有像我希望的那样在我的函数中定义。我收到错误消息“全局名称color1未定义”，即使我从一个函数返回color1，我给它一个定义的值。 这是我的代码：
import random
card = ['1','2','3','4','5','6','7','8','9','10','11','12','13','14','15','16','17','18','19','20','21','22','23','24','25','26','27','28','29','30','31','32','33','34','35','36','37','38','39','40','41','42','43','44','45','46','47','48','49','50','51','52']
def computer_card1():
return random.choice(card)
def computer_card2():
return random.choice(card)
def player_color():
color_in = input('Purple, Black or Red? ').strip().lower()
return color_in
def cards():
if computer_card1() == 1:
color1 = black
value1 = 2
if computer_card1() == 2:
color1 = black
value1 = 3
if computer_card1() == 3:
color1 = black
value1 = 4
if computer_card1() == 4:
color1 = black
value1 = 5
if computer_card1() == 5:
color1 = black
value1 = 6
if computer_card1() == 6:
color1 = black
value1 = 7
if computer_card1() == 7:
color1 = black
value1 = 8
if computer_card1() == 8:
color1 = black
value1 = 9
if computer_card1() == 9:
color1 = black
value1 = 10
if computer_card1() == 10:
color1 = black
value1 = 11
if computer_card1() == 11:
color1 = black
value1 = 12
if computer_card1() == 12:
color1 = black
value1 = 13
if computer_card1() == 13:
color1 = black
value1 = 0
if computer_card1() == 14:
color1 = black
value1 = 2
if computer_card1() == 15:
color1 = black
value1 = 3
if computer_card1() == 16:
color1 = black
value1 = 4
if computer_card1() == 17:
color1 = black
value1 = 5
if computer_card1() == 18:
color1 = black
value1 = 6
if computer_card1() == 19:
color1 = black
value1 = 7
if computer_card1() == 20:
color1 = black
value1 = 8
if computer_card1() == 21:
color1 = black
value1 = 9
if computer_card1() == 22:
color1 = black
value1 = 10
if computer_card1() == 23:
color1 = black
value1 = 11
if computer_card1() == 24:
color1 = black
value1 = 12
if computer_card1() == 25:
color1 = black
value1 = 13
if computer_card1() == 26:
color1 = black
value1 = 0
if computer_card1() == 27:
color1 = red
value1 = 2
if computer_card1() == 28:
color1 = red
value1 = 3
if computer_card1() == 29:
color1 = red
value1 = 4
if computer_card1() == 30:
color1 = red
value1 = 5
if computer_card1() == 31:
color1 = red
value1 = 6
if computer_card1() == 32:
color1 = red
value1 = 7
if computer_card1() == 33:
color1 = red
value1 = 8
if computer_card1() == 34:
color1 = red
value1 = 9
if computer_card1() == 35:
color1 = red
value1 = 10
if computer_card1() == 36:
color1 = red
value1 = 11
if computer_card1() == 37:
color1 = red
value1 = 12
if computer_card1() == 38:
color1 = red
value1 = 13
if computer_card1() == 39:
color1 = red
value1 = 0
if computer_card1() == 40:
color1 = red
value1 = 2
if computer_card1() == 41:
color1 = red
value1 = 2
if computer_card1() == 42:
color1 = red
value1 = 3
if computer_card1() == 43:
color1 = red
value1 = 4
if computer_card1() == 44:
color1 = red
value1 = 5
if computer_card1() == 45:
color1 = red
value1 = 6
if computer_card1() == 46:
color1 = red
value1 = 7
if computer_card1() == 47:
color1 = red
value1 = 8
if computer_card1() == 48:
color1 = red
value1 = 9
if computer_card1() == 49:
color1 = red
value1 = 10
if computer_card1() == 50:
color1 = red
value1 = 11
if computer_card1() == 51:
color1 = red
value1 = 12
if computer_card1() == 52:
color1 = red
value1 = 13
if computer_card2() == 1:
color2 = black
value2 = 2
if computer_card2() == 2:
color2 = black
value2 = 2
if computer_card2() == 3:
color2 = black
value2 = 4
if computer_card2() == 4:
color2 = black
value2 = 5
if computer_card2() == 5:
color2 = black
value2 = 6
if computer_card2() == 6:
color2 = black
value2 = 7
if computer_card2() == 7:
color2 = black
value2 = 8
if computer_card2() == 8:
color2 = black
value2 = 9
if computer_card2() == 9:
color2 = black
value2 = 10
if computer_card2() == 10:
color2 = black
value2 = 11
if computer_card2() == 11:
color2 = black
value2 = 12
if computer_card2() == 12:
color2 = black
value2 = 13
if computer_card2() == 13:
color2 = black
value2 = 0
if computer_card2() == 14:
color2 = black
value2 = 2
if computer_card2() == 15:
color2 = black
value2 = 3
if computer_card2() == 16:
color2 = black
value2 = 4
if computer_card2() == 17:
color2 = black
value2 = 5
if computer_card2() == 18:
color2 = black
value2 = 6
if computer_card2() == 19:
color2 = black
value2 = 7
if computer_card2() == 20:
color2 = black
value2 = 8
if computer_card2() == 21:
color2 = black
value2 = 9
if computer_card2() == 22:
color2 = black
value2 = 10
if computer_card2() == 23:
color2 = black
value2 = 11
if computer_card2() == 24:
color2 = black
value2 = 12
if computer_card2() == 25:
color2 = black
value2 = 13
if computer_card2() == 26:
color2 = black
value2 = 0
if computer_card2() == 27:
color2 = red
value2 = 2
if computer_card2() == 28:
color2 = red
value2 = 3
if computer_card2() == 29:
color2 = red
value2 = 4
if computer_card2() == 30:
color2 = red
value2 = 5
if computer_card2() == 31:
color2 = red
value2 = 6
if computer_card2() == 32:
color2 = red
value2 = 7
if computer_card2() == 33:
color2 = red
value2 = 8
if computer_card2() == 34:
color2 = red
value2 = 9
if computer_card2() == 35:
color2 = red
value2 = 10
if computer_card2() == 36:
color2 = red
value2 = 11
if computer_card2() == 37:
color2 = red
value2 = 12
if computer_card2() == 38:
color2 = red
value2 = 13
if computer_card2() == 39:
color2 = red
value2 = 0
if computer_card2() == 40:
color2 = red
value2 = 2
if computer_card2() == 41:
color2 = red
value2 = 2
if computer_card2() == 42:
color2 = red
value2 = 3
if computer_card2() == 43:
color2 = red
value2 = 4
if computer_card2() == 44:
color2 = red
value2 = 5
if computer_card2() == 45:
color2 = red
value2 = 6
if computer_card2() == 46:
color2 = red
value2 = 7
if computer_card2() == 47:
color2 = red
value2 = 8
if computer_card2() == 48:
color2 = red
value2 = 9
if computer_card2() == 49:
color2 = red
value2 = 10
if computer_card2() == 50:
color2 = red
value2 = 11
if computer_card2() == 51:
color2 = red
value2 = 12
if computer_card2() == 52:
color2 = red
value2 = 13
return color1
return color2
return value1
return value2
def main():
card1 = computer_card1()
card2 = computer_card2()
pcolor = player_color()
print ( "The cards where:",card1,",",card2,",",pcolor )
if color1 == color2:
color = color1
else:
color = 'purple'
if color == pcolor:
print ('Win')
else:
print ('Lose')
答案 0 :(得分：0)
import random
def computer_pick_card():
face = random.choice(['A', '1', '2', '3', '4', '5', '6', '7', '8', '9', '10', 'J', 'Q', 'K'])
suit = random.choice('HSDC')
return face + suit # returns eg 'QC' for Queen of Clubs or '7D' for 7 of Diamonds
def player_color():
return input('Purple, Black or Red? ').strip().lower()
def card_color(card):
suit = card[-1] # last character
if suit in 'CS':
return 'black'
elif suit in 'HD':
return 'red'
else:
raise ValueError('bad card suit = {}'.format(suit))
def main():
pcolor = player_color()
card1 = computer_pick_card()
col1 = card_color(card1)
card2 = computer_pick_card()
col2 = card_color(card2)
print("The computer chose {} ({}) and {} ({}).".format(card1, col1, card2, col2))
if col1 == col2:
winner = col1
else:
winner = 'purple'
print('Winning color is {}'.format(winner))
if pcolor == winner:
print ('You win!')
else:
print ('You lose')
if __name__=="__main__":
main()
请注意，在这种用法中，实际上挑选两张牌并进行比较会发生大量不必要的工作;你可以直接用
获得相同的结果winner = random.choice(["red", "black", "purple", "purple"])
答案 1 :(得分：0)
我的天啊！你仍然误解了很多年轻的padawan ...... :)。
让我们从variable scope开始吧。让我解释一下。
编写以下代码时，
def myfunction():
a = 5
print(a) # OK
b = a # This line fails
你会失败，因为a 本地到myfunction，也就是说它只存在于该函数中，最后一个语句引用变量python不知道。这是一个很好的功能，因为没有范围，您必须非常小心，不要在程序的任何可能发生冲突的部分中使用相同的变量名。如果它在一个小程序中很无聊，那么它对于更大的程序是强制性的（想想firefox的10.2M行代码）。
return关键字 return关键字不会在全局范围内放置变量（变量在任何时候都可用的边界）。相反，结束当前函数并将一些值传递给调用者。第一个语句突然结束了该函数，后续return永远不会到达。从调用者那里获取返回值，如下所示：
def afunction():
a = 5
return a
b = afunction()
print(b) # will print `5`
Python提供了一种方便的方法，可以以元组的形式从函数中返回多个值。人们就这样使用它：
def somefunction():
a = 7
b = "hello"
return a, b, "worlds"
sev, hel, wo = somefunction()
print(hel, sev, wo) # will print `hello 7 worlds`
最后一个主题是说好的程序具有简单的算法和复杂性在于数据。 Python有一套很棒的工具，专门用于表达和操作复杂的数据集。 Lists，tuples和dictionaries用于描述复杂数据，对其进行分组并建立关系。使用它们，您将简化很多代码，因此请尽快学会使用它们。
一些不错的读物：