Prompt-toolkit is a library for designing command line interfaces. Basically, it can be a pure Python replacement for GNU readline: it implements most of the Emacs and Vi keybindings as well as reverse search and code completion and it supports double width characters. However, it can be even much more powerful. There is syntax highlighting of the input, multiline editing, support for toolbars, custom layouts, multiple input fields and integration with other event loops (e.g. asyncio).

In this talk we will see how easy it is to create a custom command line interface: it doesn't take more than a few lines of code. Further we'll see how to add input validation, code completion and other extensions, each without much effort.

We will also have a look at ptpython. This is a Python REPL build on top of this library. We have a look at several interesting features of ptpython which can make your REPL experience even better. And finally, there is ptipython, the front-end for IPython.