Multiple "command" invocations in a single execution

[dereksz]

First Check

• I added a very descriptive title here.
• I used the GitHub search to find a similar question and didn't find it.
• I searched the Typer documentation, with the integrated search.
• I already searched in Google "How to X in Typer" and didn't find any information.
• I already read and followed all the tutorials in the docs and didn't find an answer.
• I already checked if it is not related to Typer but to Click.

Commit to Help

• I commit to help with one of those options 👆

Example Code

#!/usr/bin/env python3

# RUS AS: ./typer-test.py in typer-test.py : out t.t : go

import sys
from typing import Annotated, Dict, Optional
import typer
from pathlib import Path
from shutil import copyfile

# See: https://click-shell.readthedocs.io/en/latest/usage.html#factory-method
import click
from click_shell import make_click_shell

@click.group()
@click.pass_context
def my_app(ctx):
    pass

# Back to normal `typer` code

STATE: Dict[str, Path] = {}

app = typer.Typer(
    no_args_is_help=False,
    pretty_exceptions_short=False,
)

@app.command("in")
def cmd_in(name: Path):
    STATE["IN"] = name

@app.command("out")
def cmd_out(name: Path):
    STATE["OUT"] = name

@app.command("go")
def cmd_go():
    _in = STATE["IN"]
    _out = STATE["OUT"]
    copyfile(_in, _out)
    
@app.callback(invoke_without_command=True)
def base(ctx: typer.Context):
    if ctx.invoked_subcommand is None:
        # See: https://click-shell.readthedocs.io/en/latest/usage.html#factory-method
        shell = make_click_shell(ctx, prompt=f'{sys.argv[0]} > ', intro='Starting up...')
        shell.cmdloop()
        typer.Exit(0)

if __name__ == "__main__":
    # typer.run(main) # When only a single command
    orig_argv = sys.argv
    separators = [ idx for idx, arg in enumerate(orig_argv) if arg == ":" ]
    if not separators:
        app() # dispatch to one of multiple commands
    else: # hack for dispatching MULTIPLE command from a single command line invocation
        separators.append(len(orig_argv)) # Adding a "full-back" makes the loop logic easier
        orig_argv = orig_argv.copy()
        start_idx = 1
        for sep_idx in separators:
            if start_idx == sep_idx: # catch a separator at the end or 2 next to each other
                raise typer.BadParameter("Bad command separator layout")
            new_argv = [orig_argv[0]]
            new_argv.extend(orig_argv[start_idx:sep_idx])
            sys.argv = new_argv
            try: # Could try this instead: https://github.com/tiangolo/typer/issues/129
                app()
            except SystemExit as ex:
                if ex.args[0] != 0:
                    raise
            start_idx = sep_idx + 1

Description

I've been exploring, and I managed to integrate click_shell with typer.

This was great.

Then, I realised that that would allow me to run several command in a single execution context.

So, maybe I create commands for in, out, and go, where the first two describe data sources and destinations, complete with additional formatting options, and then go references static data structures created by the first two and cause the data to be read and written.

I've hacked something together that works. The example uses : as a command separator.

I was thinking of "pulling this down" deeper into typer and offering a PR, but then realised there's the world of type completion, and probably other things I've not even though about. (Oh, and the world of "top level" arguments (before the command) that I've not even though about.)

Wanted to share as a possibe "feature request" - happy to work on it, but would appreciate some guidance in the world of "what else do I need to fix-up"?

Operating System

Linux

Operating System Details

No response

Typer Version

0.12.3

Python Version

3.11

Additional Context

No response

[dereksz]

For the example I initially gave, this can be addressed with simple command "chaining", and is available in typer and click. However if in and out are both groups with nested commands, then chaining doesn't seem to work, as the "chain" wants to be at the nested level, and doesn't have a way to "pop out" back to the top-level. AND, I think that all of these are issues at the click level, rather than typer, so closing this out as a typer discussion for now. (Indeed, in click, a group-within-a-group generates an exception saying it's not supported.)