Python String rindex() Method

Last Updated : 22 Aug, 2022

Python String rindex() method returns the highest index of the substring inside the string if the substring is found. Otherwise, it raises ValueError.

Python String index() Method Syntax

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.

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

Python String index() Method Example

Python3

text = 'geeks for geeks'
 
result = text.rindex('geeks')
print("Substring 'geeks':", result)

Output:

Substring 'geeks': 10

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

Example 1: Python String rindex() Method with start or end index

If we provide the start and end value to check inside a string, Python String rindex() will search only inside that range.

Python3

string = "ring ring"
 
# checks for the substring in the range 0-4 of the string
print(string.rindex("ring", 0, 4))
 
# same as using 0 & 4 as start, end value
print(string.rindex("ring", 0, -5))
 
string = "101001010"
# since there are no '101' substring after string[0:3]
# thus it will take the last occurrence of '101'
print(string.rindex('101', 2))

Output:

0
0
5

Example 2: Python String rindex() Method without start and end index

Python3

string = "ring ring"
 
# search for the substring,
# from right in the whole string
print(string.rindex("ring"))
 
string = "geeks"
# this will return the right-most 'e'
print(string.rindex('e'))

Output:

5
2

Errors and Exceptions:

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

Python3

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

Exception:

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