In programming, a docstring is a comment included in source code to document the purpose of a piece of code. Unlike conventional source code comments, or even specifically formatted comments like Javadoc documentation, docstrings are not stripped from the source tree when it is parsed, but are retained throughout the runtime of the program. This allows the program to inspect these comments at run time, for instance as an interactive help system, or as metadata Computer programming (often simply programming) is the craft of implementing one or more interrelated abstract algorithms using a particular programming language to produce a concrete computer program. ... Source code (commonly just source or code) is any series of statements written in some human-readable computer programming language. ... Metadata (Greek: meta- + Latin: data information), literally data about data, is information that describes another set of data. ...

Among languages that support docstrings are Python and Lisp. Python is an interpreted, interactive programming language created by Guido van Rossum in 1990, originally as a scripting language for Amoeba OS capable of making system calls. ... Lisp is a family of computer programming languages with a long history and a distinctive fully-parenthesized syntax. ...