pyscript/docs/reference/plugins/py-terminal.md

<py-terminal>

This is one of the core plugins in PyScript, which is active by default. With it, you can print to stdout and stderr from your python code, and the output will be displayed on the page in <py-terminal>.

Configuration

You can control how <py-terminal> behaves by setting the values of the terminal, docked, and xterm fields in your configuration in your <py-config>.

For the terminal field, these are the values:

value	description
false	Don't add <py-terminal> to the page
true	Automatically add a <py-terminal> to the page
"auto"	This is the default. Automatically add a <py-terminal auto>, to the page. The terminal is initially hidden and automatically shown as soon as something writes to stdout and/or stderr

For the docked field, these are the values:

value	description
false	Don't dock <py-terminal> to the page
true	Automatically dock a <py-terminal> to the page
"docked"	This is the default. Automatically add a <py-terminal docked>, to the page. The terminal, once visible, is automatically shown at the bottom of the page, covering the width of such page

Please note that docked mode is currently used as default only when terminal="auto", or terminal default, is used.

In all other cases it's up to the user decide if a terminal should be docked or not.

For the xterm field, these are the values:

value	description
false	This is the default. The <py-terminal> is a simple <pre> tag with some CSS styling.
true or xterm	The xtermjs library is loaded and its Terminal object is used as the <py-terminal>. It's visibility and position are determined by the docked and auto keys in the same way as the default <py-terminal>

The xterm.js Terminal object can be accessed directly if you want to adjust its properties, add custom parser hooks, introduce xterm.js addons, etc. Access is best achieved by awaiting the xtermReady attribute of the <py-terminal> HTML element itself:

import js
import asyncio

async def adjust_term_size(columns, rows):
    xterm = await js.document.querySelector('py-terminal').xtermReady
    xterm.resize(columns, rows)

asyncio.ensure_future(adjust_term_size(40,10))

Some terminal-formatting packages read from specific environment variables to determine whether they should emit formatted output; PyScript does not set these variables explicitly - you may need to set them yourself, or force your terminal-formatting package into a state where it outputs correctly formatted output.

A couple of specific examples:

• the rich will not, by default, output colorful text, but passing 256 or truecolor as an argument as the color_system parameter to the Console constructor will force it to do so. (As of rich v13)
• termcolor will not, by default, output colorful text, but setting os.environ["FORCE_COLOR"] = "True" or by passing force_color=True to the colored() function will force it to do so. (As of termcolor v2.3)

Examples

<py-config>
    terminal = true
    docked = false
</py-config>

<py-script>
    print("Hello, world!")
</py-script>

This example will create a new <py-terminal>, the value "Hello, world!" that was printed will show in it.

You can also add one (or more) <py-terminal> to the page manually.

<py-script>
    print("Hello, world!")
</py-script>

<py-terminal></py-terminal>

If you include a `<py-terminal>` in the page, you can skip `terminal` from your `<py-config>`.