Question

我正在玩If Else语句，我想知道如果第一个If Else是真的，如何让它循环再次询问问题。

此外，您如何在最后添加一个通用的Else，以便为其他任何其他名称说些什么？

我在Python 2.7

上Raspberry Pi.

#!/usr/bin/python

name=""
while name !="quit":
 name = raw_input("What is your name? ")
 print "Hello", name
 import time
 time.sleep(2)
 if name == "Jack":
   print "Jack, I have decided that you are awesome."
   time.sleep(2)
   print "And I am a computer so I cannot be wrong"
 else:
   print "Oh, you are not Jack?"
   time.sleep(2)
   print "Haha, Jack is better than you"
 if name == "Ronan":
   print "Ronan, I know everything about you."
   time.sleep(2)
   print "For example, I know you hate cats."
 else:
   print "Oh, you are not Ronan?"
   time.sleep(2)
   print "Perhaps you can convince him that he loves cats"

Answer 1

您忘记在print "Haha, Jack is better than you行关闭括号。

你应该import time只有一次，在while循环之外，最好是在脚本的开头。您无需导入while name !="quit"。

if/else构造应如下所示：

if something:
    #do something

elif otherthing:
    #do something else

else:
    #if everything above fails, do this

Answer 2

你错过了这一行的结束语print "Jack, I have decided that you are awesome."最后一行的break命令将有助于终止循环。

 name=""
while name !="quit":
 name = raw_input("What is your name? ")
 print "Hello", name
 import time
 time.sleep(2)
 if name == "Jack":
   print "Jack, I have decided that you are awesome."
   time.sleep(2)
   print "And I am a computer so I cannot be wrong"
 else:
   print "Oh, you are not Jack?"
   time.sleep(2)
   print "Haha, Jack is better than you"
 if name == "Ronan":
   print "Ronan, I know everything about you."
   time.sleep(2)
   print "For example, I know you hate cats."
 else:
   print "Oh, you are not Ronan?"
   time.sleep(2)
   print "Perhaps you can convince him that he loves cats"
 if name != "jack" and name != "Ronan":
   print "I am not wrong"

 break

Answer 3

您可以使用continue将执行返回到循环的顶部。

 if name == "Jack":
   print "Jack, I have decided that you are awesome."
   time.sleep(2)
   print "And I am a computer so I cannot be wrong"
   continue

但实际上你需要重构你的if ... else语句。

你的循环终止逻辑也不太对，这样会更好：

while True:
    name = raw_input("What is your name? ")
    if name.lower() in ('quit', 'exit', 'end', 'bye'):
        break

    print "Hello", name
    if name == "Jack":
    .
    .
    .

至于你的if语句，因为你对每个名字都有else子句，所以通用的catch都有点困难。你可以在最后检查：

KNOWN_NAMES = ('Jack', 'Ronan', 'Whomever')
QUIT_VERBS = ('quit', 'q', 'exit', 'end', 'bye')

while True:
    name = raw_input("What is your name? ")
    if name.lower() in QUIT_VERBS:
        break

    if name == "Jack":
        print "Jack, I have decided that you are awesome."
        time.sleep(2)
        print "And I am a computer so I cannot be wrong"
    else:
        print "Oh, you are not Jack?"
        time.sleep(2)
        print "Haha, Jack is better than you"
    if name == "Ronan":
        # etc, etc

    if name not in KNOWN_NAMES:
        print 'I know nothing about no "%s"' % name

Python如果Else语句语法错误

3 个答案: