Library for writing console (command oriented) user interfaces. It depends only on the Python standard library.
The package makes it easy and quick to create an interactive command oriented tool. The style is similar to embedded systems, such as routers, and POSIX shells. This is not an alternate Python REPL, such as IPython or bpython. You can use it to implement a custom command interface for your application that gets customizable command parsing, custom prompts, help system, and output paging.
The docopt module is built-in, so no additional packages need to be installed.
Some notable features:
- Commands are defined as class methods.
- Command classes group commands, and can be nested, providing context-sensitive commands.
- Implicit paged output (like more).
- Command completion.
- Concise prompt string specification, similar to a shell (percent [%] expansions).
- Colored output formatting and input prompts.
- Built-in options parsing.
- Built-in help, that uses the command-method docstring.
- Wrap any object to interact with it.
- Modular design. Any component can be subclassed and enhanced.
Also includes some bonus modules:
- presentation - helper module for using Python in interactive presentations.
- debugger - enhanced debugger that uses the framework for the user interface.
Just override the
elicit.ui.BaseCommands class. Any methods defined with doc
strings become a command that can be called. The command gets an arguments
parameter that is a docopt-style pre-parsed dictionary of arguments parsed
according to the Usage: line in the doc string.
Here's a working example:
from elicit import commands from elicit import console from elicit import controller from elicit import env from elicit import parser from elicit import themes from elicit import ui class BasicCommands(commands.BaseCommands): def mycommand(self, arguments): """Perform some function. Usage: mycommand [-o] """ self._ui.print("got arguments:", arguments) def nestedusage(self, arguments): """Check nested optional usage. Usage: nestedusage [<one> [<two>]] """ self._ui.print("got arguments:", arguments) # Add as many more commands as you need. def basic_cli(): # Create The IO module. uio = console.ConsoleIO() environment = env.Environ.from_system() theme = themes.DefaultTheme() # The built-in colored theme. # Assemble the IO in user interface. theui = ui.UserInterface(uio, environment, theme) # Create the top-level command set, with the user interface. cmd = BasicCommands(theui) # Add it to a controller, and command parser. ctl = controller.CommandController(cmd) p = parser.CommandParser(ctl) # Run the CLI using the parser. p.interact()
This defines a new command, mycommand, with a singo option -o.
elicit.present subpackage has some functionality useful for interactive
presentatations using the Python REPL. Exposes some iTerm features on MacOS.
Thanks to David Beazley for the inspiration.
To invoke interactively, for testing, use:
python3 -iq -m elicit.present.presentation
An enhanced debugger that uses this CLI toolkit is also provided. A tool, eldb, is also provided that you can use instead of python3 to run a script, or module, that will enter the debugger if an uncaught exception occurs.
or, if you have a package with an if ... __main__: section:
You can also import the
elicit.debugger module in your code and call the
post_mortem function, as with pdb.
Some notable features:
- Colorized UI - stacktrace, prompt, etc.
- More informative reports, prompt shows current position in stack.
- Invoke your editor at current point.
- REPL-like evaluator
- Enter sub-REPL if desired.
- Display opcodes.