Python Prompt Toolkit
prompt_toolkit is a library for building powerful interactive command
line applications in Python.
Read the documentation on readthedocs.
Gallery
ptpython is an interactive
Python Shell, build on top of prompt_toolkit.
prompt_toolkit features
prompt_toolkit could be a replacement for GNU
readline, but it
can be much more than that.
Some features:
- Pure Python.
- Syntax highlighting of the input while typing. (For instance, with a Pygments lexer.)
- Multi-line input editing.
- Advanced code completion.
- Both Emacs and Vi key bindings. (Similar to readline.)
- Even some advanced Vi functionality, like named registers and digraphs.
- Reverse and forward incremental search.
- Works well with Unicode double width characters. (Chinese input.)
- Selecting text for copy/paste. (Both Emacs and Vi style.)
- Support for bracketed paste.
- Mouse support for cursor positioning and scrolling.
- Auto suggestions. (Like fish shell.)
- Multiple input buffers.
- No global state.
- Lightweight, the only dependencies are Pygments and wcwidth.
- Runs on Linux, OS X, FreeBSD, OpenBSD and Windows systems.
- And much more...
Feel free to create tickets for bugs and feature requests, and create pull requests if you have nice patches that you would like to share with others.
Installation
pip install prompt_toolkit
For Conda, do:
conda install -c https://conda.anaconda.org/conda-forge prompt_toolkit
About Windows support
prompt_toolkit is cross platform, and everything that you build on top
should run fine on both Unix and Windows systems. Windows support is
best on recent Windows 10 builds, for which the command line window
supports vt100 escape sequences. (If not supported, we fall back to
using Win32 APIs for color and cursor movements).
It's worth noting that the implementation is a "best effort of what is possible". Both Unix and Windows terminals have their limitations. But in general, the Unix experience will still be a little better.
Getting started
The most simple example of the library would look like this:
from prompt_toolkit import prompt
if __name__ == '__main__':
answer = prompt('Give me some input: ')
print('You said: %s' % answer)
For more complex examples, have a look in the examples directory. All
examples are chosen to demonstrate only one thing. Also, don't be
afraid to look at the source code. The implementation of the prompt
function could be a good start.
Philosophy
The source code of prompt_toolkit should be readable, concise
and efficient. We prefer short functions focusing each on one task
and for which the input and output types are clearly specified. We
mostly prefer composition over inheritance, because inheritance can
result in too much functionality in the same object. We prefer immutable
objects where possible (objects don't change after initialization).
Reusability is important. We absolutely refrain from having a changing
global state, it should be possible to have multiple independent
instances of the same code in the same process. The architecture should
be layered: the lower levels operate on primitive operations and data
structures giving -- when correctly combined -- all the possible
flexibility; while at the higher level, there should be a simpler API,
ready-to-use and sufficient for most use cases. Thinking about
algorithms and efficiency is important, but avoid premature
optimization.