【LeetCode】1668.最大重複子字符串（二）

3、使用index()和rindex()：

>>> str = "this is really a string example....wow!!!"
>>> substr = "is"
>>> print(str.index(substr)) 
2
>>> print(str.rindex(substr)) 
5
>>> print(str.rindex('123'))  
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: substring not found
>>> print(str.index('123'))   
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: substring not found

index()和rindex()

find()和rfind()

類似，不同點在於，index()和rindex()找不到子字符串後，會返回ValueError