TextLog

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

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

• Focusable
• Container

Example

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

Outputtext_log.py

import csv
import io

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

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


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 TextLogApp(App):
    def compose(self) -> ComposeResult:
        yield TextLog(highlight=True, markup=True)

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

        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(TextLog)
        text_log.write(event)


if __name__ == "__main__":
    app = TextLogApp()
    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.

---

textual.widgets.TextLog 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

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

auto_scroll class-attribute instance-attribute

auto_scroll: var[bool] = auto_scroll

Automatically scroll to the end on write.

highlight class-attribute instance-attribute

highlight: var[bool] = highlight

Automatically highlight content.

markup class-attribute instance-attribute

markup: var[bool] = markup

Apply Rich console markup.

max_lines class-attribute instance-attribute

max_lines: var[int | None] = max_lines

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

min_width class-attribute instance-attribute

min_width: var[int] = min_width

Minimum width of renderables.

wrap class-attribute instance-attribute

wrap: var[bool] = wrap

Enable word wrapping.

clear method

def clear(self):

Clear the text log.

Returns

Type	Description
Self	The TextLog instance.

render_lines method

def render_lines(self, crop):

Render the widget in to lines.

Parameters

Name	Type	Description	Default
crop	Region	Region within visible area to.	required

Returns

Type	Description
list[Strip]	A list of list of segments

write method

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

Write text or a rich renderable.

Parameters

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

Returns

Type	Description
Self	The TextLog instance.