Shiny for Python module for console you can write to

app.py

from shiny import App, reactive, render, ui, module
from shiny.session import Session
from contextlib import redirect_stdout, redirect_stderr
import asyncio
from shiny_console import Console, console_ui, console_server


# == Example usage =======================================

app_ui = ui.page_fluid(
    ui.input_task_button("go", "Go"),
    console_ui("one"),
    class_="p-3"
)

def server(input, output, session):
    console = console_server("one")

    @reactive.effect
    @reactive.event(input.go)
    async def _():
        console.clear()
        with redirect_stdout(console):
            with redirect_stderr(console):
                await asyncio.sleep(1)
                print("one")
                await asyncio.sleep(1)
                print("two")

app = App(app_ui, server)

shiny_console.py

from shiny import App, reactive, render, ui, module
from shiny.session import Session

class Console:
    def __init__(self, selector: str, session: Session):
        self._selector = selector
        self._session = session

    def write(self, s: str):
        ui.insert_ui(
            s,
            f"{self._selector} > .out",
            "beforeEnd",
            immediate=True,
            session=self._session,
        )

    def clear(self):
        ui.remove_ui(
            f"{self._selector} > .out",
            immediate=True,
            session=self._session,
        )
        ui.insert_ui(
            ui.pre(class_="out"),
            self._selector,
            "beforeEnd",
            immediate=True,
            session=self._session,
        )

    def flush(self):
        pass


@module.ui
def console_ui():
    return ui.div(
        ui.pre(class_="out"),
        id=module.resolve_id("console"),
    )


@module.server
def console_server(input, output, session):
    return Console(f"#{session.ns('console')}", session)