Python Programming with the Java™ Class Libraries: A Tutorial for Building Web and Enterprise Applications with Jython

Finding: find(), rfind(), index(), rindex(), count(), replace()

The finding functions in the string module locate a substring within a string. For example, substrings of “Python is fun” are “Pyt”, “is”, “fun”, “n is f”, and so forth. Using a substring helps in parsing string data.

The find(s, sub, [start],[end]) function finds the first position of a substring in a given string. You can set the start and stop position arguments, which determine where in the string the search will begin and end. Here's an example:

>>> str = "apple peach pear grapes apple lime lemon"
>>> position = find(str, "pear")

Here's a real-world use of find(): extracting text out of a tag when reading in an HTML file from a server.

Create some sample text embedded in HTML ...