Python 切片字符串以满足if条件

我有一系列的条件使单词多元化。如果在文件中找到它们的条件，以及如果在文件中找不到它们的条件。我已经（我想）确定了我的问题，但不确定如何解决它。我确信这与我如何分割字符串以匹配条件有关

我相信你可以在

之前阅读所有内容：

所以我会跳到前面。 以下所有

else

的目的是： **若单词不是复数，也不是专有名词，那个么：若单词以元音结尾，添加“s”。否则

-如果以“y”结尾，前面有一个辅音，请删除最后一个字母并添加“ies”

-如果以“f”结尾，请删除最后一个字母并添加“ves”

-如果以“sh”/“ch”/“z”结尾，则添加“es”

-如果以上都不适用，只需添加“s”**

逻辑必须遵循上述顺序，不能偏离

def pluralize(word):
  proper_nouns= [line.strip() for line in open (filepath)]    ### opens file when function is called, removes white spaces, and returns a list of the content within the file. 
  word_in_plural = ''                                         ### placeholders for string values.
  x = ''
  vowels = ('aeiou')                                          ### variables to apply conditional statements
  consonants = ('bcdfghjklmnpqrstvwxyz')
  dictionary = {'plural' : word_in_plural, 'status' : x}      ### dictionary definition
  if word == '':                                              
    dictionary ['plural'] = ''; dictionary ['status'] = 'empty_string'

  elif word [-1] == 's':                                     
    dictionary ['plural'] = word; dictionary ['status'] = 'already_in_plural'

  elif word.lower() in proper_nouns:                                  
    dictionary ['plural'] = word; dictionary ['status'] = 'proper_noun'

  else: 
    
   if word [-1].lower() in vowels:                                    #works
     word = word + 's' 
     dictionary ['plural'] = word; dictionary ['status'] = 'success'
        

   elif word [-2].lower() in consonants and word[-1] == 'y':          #works
     word = word [:-1] + 'ies'
     dictionary ['plural'] = word; dictionary ['status'] = 'success'
      

   elif word [-1].lower() == 'f':                                      #works
     word = word [:-1] + 'ves'
     dictionary ['plural'] = word; dictionary ['status'] = 'success'
      

   elif word [-1:-2].lower() == 's' + 'h' or 'c' + 'h':               #does not
     word = word + 'es'
     dictionary ['plural'] = word; dictionary ['status'] = 'success'
      

   elif word [:-1].lower() == 'z':                                    #works
     word = word + 'es'
     dictionary ['plural'] = word; dictionary ['status'] = 'success'
      

   elif word not in proper_nouns.lower():                             #not sure
     word = word + 's'
     dictionary ['plural'] = word; dictionary ['status'] = 'success'

输出：

failure --> {'plural': 'failures', 'status': 'success'}
----
food --> {'plural': 'foodes', 'status': 'success'}
----
Zulma --> {'plural': 'Zulma', 'status': 'proper_noun'}
----
injury --> {'plural': 'injuries', 'status': 'success'}
----
elf --> {'plural': 'elves', 'status': 'success'}
----
buzz --> {'plural': 'buzzes', 'status': 'success'}
----
computers --> {'plural': 'computers', 'status': 'already_in_plural'}
----
PCs --> {'plural': 'PCs', 'status': 'already_in_plural'}
----
 --> {'plural': '', 'status': 'empty_string'}
----
highway --> {'plural': 'highwayes', 'status': 'success'}
----
presentation --> {'plural': 'presentationes', 'status': 'success'}
----
pouch --> {'plural': 'pouches', 'status': 'success'}
----
COVID-19 --> {'plural': 'COVID-19es', 'status': 'success'}
----
adam --> {'plural': 'adam', 'status': 'proper_noun'}

食品、公路、演讲和新冠病毒19都是错误的。它们不在文件中，因此应以“s”结尾使用此选项

elif (word [-1:-2].lower() == 's' + 'h') or (word [-1:-2].lower() == 'c' + 'h'): 

---

这回答了你的问题吗？特别是关于您的

es

案例不具体，但我感谢您的帮助，但这会造成另一个问题：

buzz-->{pollular'：'buzzs'，'status'：'success'}

邮袋-->{pollular'：'backs'，'status'：'success'}

现在没有达到预期效果