str.rfind()

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

The .rfind() method searches for a substring within a string and returns the highest index where the substring is found. The “r” stands for “right” — it searches from the end of the string toward the beginning. If the substring is not found, it returns -1 instead of raising an exception.

This makes .rfind() useful when you need to locate the last occurrence of something, like the final slash in a path or the last instance of a word you want to replace.

Syntax

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

Parameters

Parameter	Type	Default	Description
sub	str	—	The substring to search for
start	int	0	Beginning index to search from
end	int	len(str)	Ending index to search up to

Return Value

Returns an integer representing the highest index where the substring is found. Returns -1 if the substring is not present in the string.

Examples

Basic search

text = "Hello, world"
print(text.rfind("l"))
# 10

print(text.rfind("z"))
# -1

Finding the last occurrence

path = "/home/user/documents/file.txt"
last_slash = path.rfind("/")
print(last_slash)
# 20

filename = path[last_slash + 1:]
print(filename)
# file.txt

Using start parameter

text = "apple banana apple cherry apple"
print(text.rfind("apple"))
# 26

# Search only in the first half of the string
print(text.rfind("apple", 0, 20))
# 13

Using start and end

text = "ababa"
print(text.rfind("aba"))
# 2

print(text.rfind("aba", 1))
# 2

Common Patterns

Check if substring exists

text = "Python is great"
if text.rfind("is") != -1:
    print("Found!")

Find the last extension in a filename

filename = "archive.tar.gz"
last_dot = filename.rfind(".")
if last_dot != -1:
    extension = filename[last_dot:]
    print(extension)
    # .gz

Replace the last occurrence

def replace_last(text, old, new):
    idx = text.rfind(old)
    if idx == -1:
        return text
    return text[:idx] + new + text[idx + len(old):]

result = replace_last("foo bar foo", "foo", "baz")
print(result)
# foo bar baz

Parse a URL’s last segment

url = "https://api.example.com/v1/users/123/profile"
last_slash = url.rfind("/")
resource_id = url[last_slash + 1:]
print(resource_id)
# profile

Edge Cases

Empty substring

text = "hello"
print(text.rfind(""))
# 5

Finding an empty string returns the length of the string because "" exists at every position, and rfind returns the highest such position.

Substring appears once

text = "hello"
print(text.rfind("o"))
# 4
print(text.rfind("e"))
# 1

When the substring appears only once, rfind and find return the same index.

Overlapping matches

text = "aaa"
print(text.rfind("aa"))
# 1

print(text.find("aa"))
# 13

With overlapping matches, rfind returns the rightmost starting position (1), while find returns the leftmost (0).

See Also

• str.find()
• str.count()
• str.startswith()