字符串索引

Question

的Python 3.5

这里是我的代码：

str1 = input("Please enter a full sentence: ").lower() 
print("Thank you, You entered:" , str1) 

str2 = input("Now please enter a word included in your sentence in anyway you like: ").lower() 

if str2 in str1: 
    print("That word was found!") 
else: 
    print("Sorry, that word was not found") 

由于它是，它会搜索输入的字（STR2），如果它是在输入（STR1发现（句子））它会说“这个词已被找到”）。如果该单词不在句子中，则会说“该单词未找到”。

我想开发这个，所以当单词被搜索和发现时，它会告诉用户单词（str2）在句子（str1）中的索引位置。例如：如果我有句子（“我喜欢用Python编码”），并搜索单词（“代码”），程序应该说“该单词在索引位置：4”。

顺便说一句，代码不区分大小写，因为它将所有的单词转换成小写的.lower。

如果有人可以给我一些建议，那么这将非常感激！

Answer 1

您可以取代您的if ... else本：

try: 
    print("That word was found at index %i!"% (str1.split().index(str2) + 1)) 
except ValueError: 
    print("Sorry, that word was not found") 

Answer 2

print("That word was found at index %i!"% (str1.split().index(str2))) 

这将打印str1中第一次出现str2的索引。
完整的代码是：

str1 = input("Please enter a full sentence: ").lower() 
print("Thank you, You entered:" , str1) 

str2 = input("Now please enter a word included in your sentence in anyway you like: ").lower() 

if str2 in str1: 
    print("That word was found!") 
    print("that word was found in index position: %i!"% (str1.split().index(str2))) 

，str1.index（STR2））
其他： 打印（ “对不起，这个词没有找到”）

Answer 3

str2 = 'abcdefghijklmnopqrstuvwxyz' 
str1 = 'z' 
index = str2.find(str1) 
if index != -1: 
    print 'That word was found in index position:',index 
else: 
    print 'That word was not found' 

这将打印在STR2其中str1指数

Answer 4

您可以使用split（）方法：它在字符串值上调用并返回字符串列表。那么你使用index（）方法来查找字符串的索引。

str1 = input("Please enter a full sentence: ").lower() 
print("Thank you, You entered:" , str1) 
str2 = input("Now please enter a word included in your sentence in anyway you like: ").lower() 

if str2 in str1: 
    a = str1.split() # you create a list 
    # printing the word and index a.index(str2) 
    print('The ', str2,' was find a the index ', a.index(str2)) 
    print("That word was found!") 
else: 
    print("Sorry, that word was not found")