Python字符串 rindex() 方法

如果找到子字符串， Python String rindex() 方法返回字符串内子字符串的最高索引。否则，它会引发异常。

Syntax: 

str.rindex(sub, start, end)

Parameters: 

• sub : It’s the substring which needs to be searched in the given string.
• start : Starting position where sub is needs to be checked within the string.
• end : Ending position where suffix is needs to be checked within the string.

Note: If start and end indexes are not provided then by default it takes 0 and length-1 as starting and ending indexes where ending indexes is not included in our search.

Return:

Returns the highest index of the substring inside the string if substring is found. Otherwise it raises an exception. 

Errors and Exceptions: 

ValueError: This error is raised when the argument string is not found in the target string.

示例 1

input: text = 'geeks for geeks'
       result = text.rindex('geeks')
output: 10

input: text = 'geeks for geeks'
       result = text.rindex('ge')
output: 10

Python3

# Python code to demonstrate working of rindex()
text = 'geeks for geeks'
 
result = text.rindex('geeks')
print("Substring 'geeks':", result)

输出：

Substring 'geeks': 10

示例 2

Python3

# Python code to demonstrate error by rindex()
text = 'geeks for geeks'
 
result = text.rindex('pawan')
print("Substring 'pawan':", result)

错误：

Traceback (most recent call last):
  File "/home/dadc555d90806cae90a29998ea5d6266.py", line 6, in 
    result = text.rindex('pawan')
ValueError: substring not found

示例 3

Python3

# Python code to demonstrate working of rindex()
# with range provided
quote = 'geeks for geeks'
 
# Substring is searched in ' geeks for geeks'
print(quote.rindex('ge', 2))
 
# Substring is searched in 0 to 10 range
print(quote.rindex('geeks', 0, 10))

输出：

10
0