Python Prompt Toolkit

prompt_toolkit is a library for building powerful interactive command lines and terminal applications in Python.

It can be a pure Python replacement for GNU readline, but it can be much more than that.

Some features:

• Syntax highlighting of the input while typing. (For instance, with a Pygments lexer.)
• Multi-line input editing.
• Advanced code completion.
• Selecting text for copy/paste. (Both Emacs and Vi style.)
• Mouse support for cursor positioning and scrolling.
• Auto suggestions. (Like fish shell.)
• No global state.

Like readline:

• Both Emacs and Vi key bindings.
• Reverse and forward incremental search.
• Works well with Unicode double width characters. (Chinese input.)

Works everywhere:

• Pure Python. Runs on all Python versions from 2.6 up to 3.4.
• Runs on Linux, OS X, OpenBSD and Windows systems.
• Lightweight, the only dependencies are Pygments, six and wcwidth.
• No assumptions about I/O are made. Every prompt_toolkit application should also run in a telnet/ssh server or an asyncio process.

Two use cases: prompts versus full screen terminal applications

prompt_toolkit was in the first place meant to be a replacement for readline. However, when it became more mature, we realised that all the components for full screen applications are there and prompt_toolkit is very capable of handling many use cases. Pyvim and pymux are examples of full screen applications.

Basically, at the core, prompt_toolkit has a layout engine, that supports horizontal and vertical splits as well as floats, where each “window” can display a user control. The API for user controls is simple yet powerful.

When prompt_toolkit is used to simply read some input from the user, it uses a rather simple built-in layout. One that displays the default input buffer and the prompt, a float for the autocompletions and a toolbar for input validation which is hidden by default.

For full screen applications, usually we build the layout ourself, because it’s very custom.

Further, there is a very flexible key binding system that can be programmed for all the needs of full screen applications.

Installation

pip install prompt_toolkit

For Conda, do:

conda install -c https://conda.anaconda.org/conda-forge prompt_toolkit

Getting started

The following snippet is the most simple example, it uses the prompt() function to asks the user for input and returns the text. Just like (raw_)input.

from __future__ import unicode_literals
from prompt_toolkit import prompt

text = prompt('Give me some input: ')
print('You said: %s' % text)

For more information, start reading the building prompts section.

Thanks to:

Thanks to all the contributors for making prompt_toolkit possible.

Also, a special thanks to the Pygments and wcwidth libraries.

Table of contents

• Gallery
  • Ptpython, a Python REPL
  • Pyvim, a Vim clone
  • Pymux, a terminal multiplexer (like tmux) in Python
• Building prompts
  • Hello world
  • Syntax highlighting
  • Colors
    • Using a Pygments style
    • Coloring the prompt itself
    • Printing text (output) in color
  • Autocompletion
    • A custom completer
  • Input validation
  • History
  • Auto suggestion
  • Adding a bottom toolbar
  • Adding a right prompt
  • Vi input mode
  • Adding custom key bindings
    • Enable key bindings according to a condition
    • Dynamically switch between Emacs and Vi mode
  • Other prompt options
    • Multiline input
    • Passing a default
    • Mouse support
    • Line wrapping
    • Password input
  • Prompt in an asyncio application
• Building full screen applications
  • Running the application
  • Key bindings
  • Creating a layout
    • The rendering flow
    • Input processors
    • The TokenListControl
    • Custom user controls
    • The Window class
  • Buffers
  • The focus stack
  • The Application instance
  • Filters (reactivity)
  • Input hooks
  • Running on the asyncio event loop
• Architecture
• Reference
  • Application
  • Buffer
  • Selection
  • Clipboard
  • Auto completion
  • Document
  • Enums
  • History
  • Interface
  • Keys
  • Style
  • Reactive
  • Shortcuts
  • Validation
  • Auto suggestion
  • Renderer
  • Layout
  • Token
  • Filters
  • Key binding
  • Eventloop
  • Input and output

Indices and tables

• Index
• Module Index
• Search Page

Prompt_toolkit was created by Jonathan Slenders.