rfind

rfind is a string method available in many programming languages, including Python. It is used to search for a substring within a larger string and return the highest index in the string where the substring is found. If the substring is not found, the method returns -1. The search for the substring proceeds from right to left.

The rfind method typically accepts two optional arguments: the substring to search for, and an optional starting and ending index to specify a slice of the string to search within. For example, in Python, string.rfind(substring, start, end) will search for substring within string[start:end]. If the start and end arguments are omitted, the entire string is searched.

This method is useful for tasks where you need to locate the last occurrence of a pattern within a string. For instance, it can be used to find the file extension of a filename by searching for the last dot ('.') or to parse data where a specific delimiter appears multiple times and you are interested in the final instance. Unlike the find method, which searches from left to right, rfind guarantees finding the rightmost occurrence.