RichLog

A RichLog is a widget which displays scrollable content that may be appended to in realtime.

Call RichLog.write with a string or Rich Renderable to write content to the end of the RichLog. Call RichLog.clear to clear the content.

Tip

See also Log which is an alternative to RichLog but specialized for simple text.

• Focusable
• Container

Example

The example below shows an application showing a RichLog with different kinds of data logged.

Outputrich_log.py

import csv
import io

from rich.syntax import Syntax
from rich.table import Table

from textual import events
from textual.app import App, ComposeResult
from textual.widgets import RichLog

CSV = """lane,swimmer,country,time
4,Joseph Schooling,Singapore,50.39
2,Michael Phelps,United States,51.14
5,Chad le Clos,South Africa,51.14
6,László Cseh,Hungary,51.14
3,Li Zhuhao,China,51.26
8,Mehdy Metella,France,51.58
7,Tom Shields,United States,51.73
1,Aleksandr Sadovnikov,Russia,51.84"""


CODE = '''\
def loop_first_last(values: Iterable[T]) -> Iterable[tuple[bool, bool, T]]:
    """Iterate and generate a tuple with a flag for first and last value."""
    iter_values = iter(values)
    try:
        previous_value = next(iter_values)
    except StopIteration:
        return
    first = True
    for value in iter_values:
        yield first, False, previous_value
        first = False
        previous_value = value
    yield first, True, previous_value\
'''


class RichLogApp(App):
    def compose(self) -> ComposeResult:
        yield RichLog(highlight=True, markup=True)

    def on_ready(self) -> None:
        """Called  when the DOM is ready."""
        text_log = self.query_one(RichLog)

        text_log.write(Syntax(CODE, "python", indent_guides=True))

        rows = iter(csv.reader(io.StringIO(CSV)))
        table = Table(*next(rows))
        for row in rows:
            table.add_row(*row)

        text_log.write(table)
        text_log.write("[bold magenta]Write text or any Rich renderable!")

    def on_key(self, event: events.Key) -> None:
        """Write Key events to log."""
        text_log = self.query_one(RichLog)
        text_log.write(event)


if __name__ == "__main__":
    app = RichLogApp()
    app.run()

Reactive Attributes

Name	Type	Default	Description
highlight	bool	False	Automatically highlight content.
markup	bool	False	Apply Rich console markup.
max_lines	int	None	Maximum number of lines in the log or None for no maximum.
min_width	int	78	Minimum width of renderables.
wrap	bool	False	Enable word wrapping.

Messages

This widget sends no messages.

Bindings

This widget has no bindings.

Component Classes

This widget has no component classes.

---

textual.widgets.RichLog class

def __init__(
    self,
    *,
    max_lines=None,
    min_width=78,
    wrap=False,
    highlight=False,
    markup=False,
    auto_scroll=True,
    name=None,
    id=None,
    classes=None,
    disabled=False
):

Bases: ScrollView

A widget for logging text.

Parameters

Parameter	Default	Description
max_lines int | None	None	Maximum number of lines in the log or None for no maximum.
min_width int	78	Minimum width of renderables.
wrap bool	False	Enable word wrapping (default is off).
highlight bool	False	Automatically highlight content.
markup bool	False	Apply Rich console markup.
auto_scroll bool	True	Enable automatic scrolling to end.
name str | None	None	The name of the text log.
id str | None	None	The ID of the text log in the DOM.
classes str | None	None	The CSS classes of the text log.
disabled bool	False	Whether the text log is disabled or not.

auto_scroll instance-attribute class-attribute

auto_scroll: var[bool] = auto_scroll

Automatically scroll to the end on write.

highlight instance-attribute class-attribute

highlight: var[bool] = highlight

Automatically highlight content.

highlighter instance-attribute

highlighter: Highlighter = ReprHighlighter()

Rich Highlighter used to highlight content when highlight is True

markup instance-attribute class-attribute

markup: var[bool] = markup

Apply Rich console markup.

max_lines instance-attribute class-attribute

max_lines: var[int | None] = max_lines

Maximum number of lines in the log or None for no maximum.

min_width instance-attribute class-attribute

min_width: var[int] = min_width

Minimum width of renderables.

wrap instance-attribute class-attribute

wrap: var[bool] = wrap

Enable word wrapping.

clear method

def clear(self):

Clear the text log.

Returns

Type	Description
Self	The RichLog instance.

write method

def write(
    self,
    content,
    width=None,
    expand=False,
    shrink=True,
    scroll_end=None,
):

Write text or a rich renderable.

Parameters

Parameter	Default	Description
content RenderableType | object	required	Rich renderable (or text).
width int | None	None	Width to render or None to use optimal width.
expand bool	False	Enable expand to widget width, or False to use width.
shrink bool	True	Enable shrinking of content to fit width.
scroll_end bool | None	None	Enable automatic scroll to end, or None to use self.auto_scroll.

Returns

Type	Description
Self	The RichLog instance.