爲什麼我不能在這段代碼上使用break，我可以使用什麼呢？ python

Question

我正在做的任務是開發一個程序，用於識別句子中的單個單詞，將它們存儲在一個列表中，並用該單詞在列表中的位置替換原始句子中的每個單詞。

sentencelist=[] #variable list for the sentences 
word=[] #variable list for the words 
positions=[] 
words= open("words.txt","w") 
position= open("position.txt","w") 

question=input("Do you want to enter a sentence? Answers are Y or N.").upper() 
if question=="Y": 
    sentence=input("Please enter a sentance").upper() #sets to uppercase so it's easier to read 
    sentencetext=sentence.isalpha or sentence.isspace() 
    while sentencetext==False: #if letters have not been entered 
     print("Only letters are allowed") #error message 
     sentence=input("Please enter a sentence").upper() #asks the question again 
     sentencetext=sentence.isalpha #checks if letters have been entered this time 

    word = sentence.split(' ') 
    for (i, check) in enumerate(word): #orders the words 
     print(sentence) 

     word = input("What word are you looking for?").upper() #asks what word they want 
     if (check == word): 
      positionofword=print("your word is in this position:", i+1) 
      positionofword=str(positionofword) 
     else: 
      print("this didn't work") #print error message 

elif question=="N": 
    print("The program will now close") 
else: 
print("you did not enter one of the prescribed letters") 

words.write(word + " ") 
position.write(positionofword + " ") 

，我的問題是，我被困在的循環：

word = input("What word are you looking for?").upper() #asks what word they want 
    if (check == word): 
     positionofword=print("your word is in this position:", i+1) 
     positionofword=str(positionofword) 
    else: 
     print("this didn't work") #print error message 

因此這意味着我不能得到的話到文件中。我曾嘗試使用break，但這對我來說並不奏效，因爲我無法將文字輸入到文件中。

我是這個網站的新手，但我一直在追蹤很長一段時間。希望這是對的，如果我說錯了話，我會接受批評。

Answer 1

您在for循環中的邏輯不正確 - 而不是一次詢問用戶想要查找的單詞，而是詢問句子中的每個單詞，並且只有當它們輸入了所需的單詞時才匹配當前單詞正在被檢查。您還將爲句子中的每個單詞打印一次該句子。重構它像這樣：

print(sentence) 
sentence_words = sentence.split(' ') 
word = input("What word are you looking for?").upper() #asks what word they want 
for (i, check) in enumerate(sentence_words): #orders the words 
    if (check == word): 
     print("your word is in this position:", i+1) 
     positionofword=i+1 
     break 
else: 
    print("This didn't work")