The syntax of rindex() is:

str.rindex(sub[, start[, end]] )

rindex() Parameters

rindex() method takes three parameters:

• sub - substring to be searched in the str string.
• start and end(optional) - substring is searched within str[start:end]

Return Value from rindex()

• If substring exists inside the string, it returns the highest index in the string where the substring is found.
• If substring doesn't exist inside the string, it raises a ValueError exception.

rindex() method is similar to rfind() method for strings.

The only difference is that rfind() returns -1 if the substring is not found, whereas rindex() throws an exception.

Example 1: rindex() With No start and end Argument

quote = 'Let it be, let it be, let it be'

result = quote.rindex('let it')
print("Substring 'let it':", result)
  
result = quote.rindex('small')
print("Substring 'small ':", result)

Output

Substring 'let it': 22
Traceback (most recent call last):
  File "...", line 6, in <module>
    result = quote.rindex('small')
ValueError: substring not found

Note: Index in Python starts from 0 and not 1.

Example 2: rindex() With start and end Arguments

quote = 'Do small things with great love'

# Substring is searched in ' small things with great love' 
print(quote.rindex('t', 2))

# Substring is searched in 'll things with'
print(quote.rindex('th', 6, 20))

# Substring is searched in 'hings with great lov'
print(quote.rindex('o small ', 10, -1))

Output

25
18
Traceback (most recent call last):
  File "...", line 10, in <module>
    print(quote.rindex('o small ', 10, -1))
ValueError: substring not found

Also Read:

• Python String index()
• Python String rfind()