neorepl

A small toolkit for building custom Python shells. Zero dependencies, Python 3.9+.

from neorepl import Shell

shell = Shell({"answer": 42}, prompt="my> ", history_file="~/.my_history")

@shell.command("greet", help="Say hello")
def greet(sh, name="world"):
    sh.print(f"Hello, {name}!")

@shell.on("pre_run")                 # rewrite input before it executes
def rewrite(sh, source):
    if source.strip() == "ll":
        return "print(sorted(globals()))"

shell.run()

Features

• Commands: %name args lines handled by @shell.command (prefix configurable). Built-ins: %help %exit %vars %reset %run %history.
• Hooks: start, exit, pre_run (can rewrite input), post_run, error, command.
• Prompts: static strings or callable(shell, more) -> str.
• Display: swap formatter= to pretty-print results (e.g. pprint.pformat, rich).
• Tab completion for names, dotted attributes, and commands (via readline).
• Persistent history with history_file=.
• Embedding: neorepl.embed() opens a shell with the caller's variables.

Develop

pip install -e ".[dev]"
pytest
python examples/demo.py