python - 初学者Python : Accumulator loop function

Question

我是Python的初学者，我有一个作业，要求我使用确定循环、字符串累加器和连接来打印一首歌曲。问题是，我能够以明确的循环打印出每个节(这首歌假设有 3 节歌曲，因此范围设置为 3)，并且在创建每个节之前，它要求用户输入一个动物，它是声音(它的老麦克唐纳)。我完成了作业的第一部分，即在用户输入后打印出每个节，但第二部分要求将所有节(总共 3 节)连接到整首歌曲中。因此，最终的结果是将各个节组合在一起形成一首歌曲。问题是，鉴于我必须更新歌曲，然后在最后输出整首歌曲，如何使用累加器？附件是我的代码:(注意这是python 2.7.5)

def main():


    for stanza in range(3):
        animal = raw_input("What animal? ")
        animalSound = raw_input("What sound does a %s make? " %(animal))

        print
        print "\t Old MacDonald had a farm, E-I-E-I-O,"
        print "And on his farm he had a %s, E-I-E-I-O" %(animal)
        print "With a %s-%s here - " %(animalSound, animalSound)
        print "And a %s-%s there - " %(animalSound, animalSound)
        print "Here a %s there a %s" %(animalSound, animalSound)
        print "Everywhere a %s-%s" %(animalSound, animalSound)
        print "Old MacDonald had a farm, E-I-E-I-O"
        print

Answer 1

通过“累加器”，我假设您指的是连续添加到前一个字符串的模式。这可以通过运算符+=来实现。

通过“连接”，我假设您指的是字符串运算符+。

根据您自己的规则，您不允许使用 % 运算符。

你可以这样做:

song = ''  # Accumulators need to start empty
for _ in range(3):  # Don't really need the stanza variable
    animal = raw_input("What animal? ")
    animalSound = raw_input("What sound does a %s make? " %(animal))

    song += "Old MacDonald had an errno. EIEIO\n"
    song += "His farm had a " + animal + " EIEIO\n"
    song += "His " + animal + "made a noise: " + animalSound + "\n"
print song

等等

我相信这就是您的作业所要求的，但要意识到这会不被视为“好的”或“Pythonic”代码。特别是字符串积累效率低下——更喜欢列表推导式和 str.join()。