Action Completer

A fairly simple method for registering callables as prompt-toolkit completions.

This package provides the basic features to easily construct a custom completer using decorators to reduce the amount of boilerplate needed to build basic tooling through prompt-toolkit. A quick example is provided below, but if you are interested in the available features and patterns you should read through the documentation.

This is a project that I originally created for myself several times when building personal utilities with prompt-toolkit, and figured it might be useful for other people to eventually use or extend. As a side-effect of this being a personal utility, the provided functionality may not exactly fit what you are looking for and the provided tests do not check all edge cases properly yet.

from pathlib import Path

from action_completer import ActionCompleter
from prompt_toolkit.shortcuts import prompt
from prompt_toolkit.completion import PathCompleter
from prompt_toolkit.validation import Validator

completer = ActionCompleter()


@completer.action("cat")
@completer.param(
  PathCompleter(),
  cast=Path,
  validators=[
      Validator.from_callable(
        lambda p: Path(p).is_file(),
        error_message="Path is not an existing file"
      )
  ]
)
def _cat_action(filepath: Path):
  with filepath.open("r") as file_handle:
      print(file_handle.read())


prompt_result = prompt(
  ">>> ",
  completer=completer,
  validator=completer.get_validator()
)
completer.run_action(prompt_result)