logging with RichHandler

[bphunter1972]

I'm pretty surprised this isn't functioning as expected when running textual run --dev.

The messages make it to the screen, but they are all garbled.

I know about textual.log, but as I am adding a TUI front-end to another tool (which itself uses rich logging), I cannot readily swap it out.

Textual diagnosis:

Textual Diagnostics

Versions

Name	Value
Textual	0.15.1
Rich	13.3.2

Python

Name	Value
Version	3.8.10
Implementation	CPython
Compiler	Clang 6.0 (clang-600.0.57)
Executable	/Users/bphunter/Library/Caches/pypoetry/virtualenvs/gviz-AtLwRJRq-py3.8/bin/python

Operating System

Name	Value
System	Darwin
Release	22.3.0
Version	Darwin Kernel Version 22.3.0: Mon Jan 30 20:42:11 PST 2023; root:xnu-8792.81.3~2/RELEASE_X86_64

Terminal

Name	Value
Terminal Application	iTerm.app (3.4.19)
TERM	xterm-256color
COLORTERM	truecolor
FORCE_COLOR	Not set
NO_COLOR	Not set

Rich Console options

Name	Value
size	width=164, height=89
legacy_windows	False
min_width	1
max_width	164
is_terminal	True
encoding	utf-8
max_height	89
justify	None
overflow	None
no_wrap	False
highlight	None
markup	None
height	None

[github-actions]

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[willmcgugan]

You can't have both a TUI and RichHandler writing in the same terminal. One would make the other unreadable. And you can't expect a logging handler in your app to know anything about a console in a different process.

I can see there being a dedicated Textual logging handler eventually. But that would still require you to be able to configure logging. You almost certainly can configure your logging to go to a file or stdout using the logging API. Even if the logging was initialised by a library. See the docs on logging config, in particular disable_existing_loggers

[bphunter1972]

Yes, I've added a FileHandler instead.

But I do not need the TUI and the RichHandler going to the same terminal. I was hoping it could go to the dev console.

[willmcgugan]

If you log to stdout with StreamHandler it will go to the dev console.

[bphunter1972]

I must have misunderstood, as that's definitely not what I'm seeing. When I set up logging with the StreamHandler to stdout, I'm seeing the log messages overwrite my App's display, and it's only re-drawn if I hover over the text.

This is after launching my app with textual run --dev, and having the console up in another terminal.

I have something along these lines:

import logging
from sys import stdout
from textual import log
...
log = logging.getLogger(__name__)
log_handler = logging.StreamHandler(stdout)
logging.basicConfig(level=logging.INFO, format="%(message)s", datefmt="[%X]", handlers=[log_handler])
...
    def on_input_submitted(self, message):
        log.info(f"received {message.value}")
        message.input.value = "> "

Here's what the upper corner of the display then looks like:

Note that this happens whether it's to stdout or stderr.

[willmcgugan]

I think the problem may be that StreamHandler holds a reference to stdout, which prevents Textual from capturing it.

You could try configuring the logging in App.on_mount

Next release should have a dedicated Textual logger.

[bphunter1972]

That'd be great! Thanks!
Looks like you opened up #2130 on this.