Python String rindex() method

Python String rindex()

Python String.rindex() method returns the index of last occurrence of specified value in given string. We can also specify the bounds in the strings, in which the search for the given value has to happen, via start and end parameters.

If the value is not present in this string, rindex() returns raises ValueError. In fact, this behavior is the only difference between str.rindex() method and str.rfind() method.

In this tutorial, we will learn the syntax and examples for rindex() method of String class.

Syntax

The syntax of String rindex() method in Python is

str.rindex(value, start, end)

where

Parameter	Required/ Optional	Description
value	Required	A string. Index of last occurrence of this value in the string has to be returned.
start	Optional	An integer. The index from which, the value has to be searched in this string.
end	Optional	An integer. The index until which, the value has to be searched in this string.

Examples

rindex() with Default Parameter Values

In the following program, we take a string 'abcd-abcd-abcd' in x, and find the index of the value 'bc' in the string x.

Example.py

x = 'abcd-abcd-abcd'
value = 'cd'
result = x.rindex(value)
print("Index :", result)

Output

Index : 12

Explanation

'a b c d - a b c d - a  b  c  d'
 0 1 2 3 4 5 6 7 8 9 10 11 12 13
                           c  d  : index of 'cd' is 12

The index of last occurrence of value 'cd' is 12.

Even though there are multiple occurrences of the given value 'cd' in this string, rindex() method returns only the index of last occurrence.

rindex() with Value not in String

We already know that rindex() raises a ValueError if the specified value is not present in the string.

Example.py

x = 'abcd-abcd-abcd'
value = 'xy'
result = x.rindex(value)
print("Index :", result)

Output

Traceback (most recent call last):
  File "/Users/tutorialkart/PythonTutorial/Example.py", line 3, in <module>
    result = x.rindex(value)
ValueError: substring not found

rindex() with Specific Start

In the following program, we will specify a starting position/index from which the search for the value value in the string has to happen.

Example.py

x = 'abcd-abcd-abcd'
value = 'cd'
start = 5
result = x.rindex(value, start)
print("Index :", result)

Output

Index : 12

Explanation

'a b c d - a b c d - a  b  c  d'
 0 1 2 3 4 5 6 7 8 9 10 11 12 13 
           |
           start=5 from this position
                           c  d   : index of 'cd' is 12

rindex() with Specific Start and End

In the following program, we will specify the bounds [start, end] for index, for searching the given value in the string.

Example.py

x = 'abcd-abcd-abcd'
value = 'cd'
start = 5
end = 9
result = x.rindex(value, start, end)
print("Index :", result)

Output

Index : 7

Conclusion

In this Python Tutorial, we learned how to find the index of last occurrence of specified value in given string, using String method – rindex().