Question

为了练习正则表达式，我正在尝试创建一个类似于Zork的非常简单的基于文本的游戏。但是我似乎无法使用正则表达式来运行代码。

Movement.py

import re

def userMove():
    userInput = raw_input('Which direction do you want to move?')
    textArray = userInput.split()
    analyse = [v for v in textArray if re.search('north|east|south|west|^[NESW]', v, re.IGNORECASE)]

   print textArray
   print analyse

   movement = 'null'
   for string in analyse:
       if string is 'North' or 'n':
          movement = 'North'
       elif string is 'East'or'e':
          movement = 'East'
       elif string is 'South'or's':
          movement = 'South'
       elif string is 'West'or'w':
          movement = 'West'

print movement

if / elif Sample Run

>>> import movement
>>> moves = movement.userMove()
Which direction do you want to move?Lets walk East
['Lets', 'walk', 'East']
['East']
North

如果运行样品

>>> import movement
>>> moves = movement.userMove()
Which direction do you want to move?I`ll run North
['I`ll', 'run', 'North']
['North']
West

如果for循环会不断将movement设置为北;并使用if语句而不是elif将其设置为West。正则表达式使用userInput代替textArray会导致方法将movement保留为空。

修改在进一步测试和更改代码之后，我确信正则表达式很好，这是if语句或for循环的错误。

Answer 1

您的问题出在这些if声明中：

if string is 'North' or 'n':
    movement = 'North'
elif string is 'East'or'e':
    movement = 'East'
elif string is 'South'or's':
    movement = 'South'
etc...

它们的效果并不像你期望的那样。首先，您不应将字符串与is进行比较 - 您应该使用==。其次，该陈述的评估更像是：

if (string is 'North') or 'n':
    movement = 'North'

因此，'n'始终为True - 意味着您的movement变量始终设置为North。

请改为尝试：

if string in ('North', 'n'):
    etc...

Answer 2

错字：

 elif string == 'South':
    movement == 'South'
    print 'Go South'

替换==与=

Answer 3

更正后的代码。 if string == 'South':块中的错字＆amp;您应该使用analyse代替textarray

import re

def userMove():
    userInput = raw_input('Which direction do you want to move?')
    textArray = userInput.split()
    analyse = [v for v in textArray if re.search('[N|n]orth|[E|e]ast|[S|s]outh|[W|w]est', v)]

print analyse

movement = 'null'
for string in analyse:
    if string == 'North':
        movement = 'North'
        print 'Go North'

    elif string == 'East':
        movement = 'East'
        print 'Go East'

    elif string == 'South':
        movement = 'South'
        print 'Go South'

    elif string == 'West':
        movement = 'West'
        print'Go West'

return movement

Python 2.7＆amp;正则表达式：如果语句返回，则返回false

3 个答案: