我如何修正代码，以便在输入字符时只找到单词的位置而不找到包含字符的单词？

Question

sentence = input("Please enter a sentence excluding punctuation")



chars = set('0123456789!"£$%^&*()_-+={}[];:@#~/?.,<>\|`¬')
while any((c in chars) for c in sentence):
    sentence = input("Please enter another sentence excluding punctuation")
else:
    print('Your sentence is fine')
sentence = sentence.upper()

locateword = input ("Enter a word from the inputted sentence to locate")
locateword=locateword.upper()


while locateword not in sentence:

    locateword = input ("Enter another word from the inputted sentence to locate")
    locateword=locateword.upper()
else:
    print ("Your word is fine")

sentence = sentence.split()

for (position,words) in enumerate(sentence):
    if (locateword in words):
        print ("The position of your word is",position+1)

This code finds the position of an inputted word in the inputted sentence. However when a single character is the word to be located, the code finds the position of the word that contains that character, how could I fix this code so that this doesn't happen? For example, when the sentence is "I like football" and the word is "ball", the position returned is 3 as "ball" is found in "football", but I do not want this to happen.

Answer 1

也许：

for (position,words) in enumerate(sentence):
    if (upper(locateword) == upper(words)): #case insensitive
        print ("The position of your word is",position+1)

尽管这不是你的问题，但检查字符串是否包含字母数字字符的更好方法是：

import re
sentence = input("Please enter a sentence excluding punctuation")
if re.search(r"\W", sentence):
    sentence = input("Please enter another sentence excluding punctuation")
else: print("Your sentence is ok!")

完整代码：

import re
sentence = input("Please enter a sentence excluding punctuation: ")
while( re.search(r"\W ", sentence)):
    sentence = input("Please enter another sentence excluding punctuation: ")
print("Your sentence is ok!")

sentence = sentence.split(" ")

locateword = input("Enter a word: ")
while(locateword.lower() not in [x.lower() for x in sentence]):
    locateword = input("Enter another word: ")

for (position,words) in enumerate(sentence):
    if (locateword.upper() == words.upper()): #case
        print ("The position of your word is",position+1)