move expensive imports out of module scope

docs/examples/guide/command_palette/command01.py

@@ -3,8 +3,6 @@
 from functools import partial
 from pathlib import Path
 
-from rich.syntax import Syntax
-
 from textual.app import App, ComposeResult
 from textual.command import Hit, Hits, Provider
 from textual.containers import VerticalScroll
@@ -53,6 +51,8 @@ def compose(self) -> ComposeResult:
 
     def open_file(self, path: Path) -> None:
         """Open and display a file with syntax highlighting."""
+        from rich.syntax import Syntax
+
         syntax = Syntax.from_path(
             str(path),
             line_numbers=True,

src/textual/app.py

@@ -15,7 +15,6 @@
 import platform
 import sys
 import threading
-import unicodedata
 import warnings
 from asyncio import Task
 from concurrent.futures import Future
@@ -56,12 +55,10 @@
 from rich.control import Control
 from rich.protocol import is_renderable
 from rich.segment import Segment, Segments
-from rich.traceback import Traceback
 
 from . import Logger, LogGroup, LogVerbosity, actions, constants, events, log, messages
 from ._animator import DEFAULT_EASING, Animatable, Animator, EasingFunction
 from ._ansi_sequences import SYNC_END, SYNC_START
-from ._asyncio import create_task
 from ._callback import invoke
 from ._compose import compose
 from ._compositor import CompositorUpdate
@@ -84,7 +81,6 @@
 from .drivers.headless_driver import HeadlessDriver
 from .features import FeatureFlag, parse_features
 from .file_monitor import FileMonitor
-from .filter import ANSIToTruecolor, DimFilter, LineFilter, Monochrome
 from .geometry import Offset, Region, Size
 from .keys import (
     REPLACED_KEYS,
@@ -114,6 +110,7 @@
 
     # Unused & ignored imports are needed for the docs to link to these objects:
     from .css.query import WrongType  # type: ignore  # noqa: F401
+    from .filter import LineFilter
     from .message import Message
     from .pilot import Pilot
     from .widget import MountError  # type: ignore  # noqa: F401
@@ -385,11 +382,15 @@ def __init__(
         environ = dict(os.environ)
         no_color = environ.pop("NO_COLOR", None)
         if no_color is not None:
+            from .filter import Monochrome
+
             self._filters.append(Monochrome())
 
         for filter_name in constants.FILTERS.split(","):
             filter = filter_name.lower().strip()
             if filter == "dim":
+                from .filter import ANSIToTruecolor, DimFilter
+
                 self._filters.append(ANSIToTruecolor(terminal_theme.DIMMED_MONOKAI))
                 self._filters.append(DimFilter())
 
@@ -1137,6 +1138,8 @@ def get_key_display(self, key: str) -> str:
 
     async def _press_keys(self, keys: Iterable[str]) -> None:
         """A task to send key events."""
+        import unicodedata
+
         app = self
         driver = app._driver
         assert driver is not None
@@ -1282,7 +1285,7 @@ async def run_app(app: App) -> None:
 
         # Launch the app in the "background"
         active_message_pump.set(app)
-        app_task = create_task(run_app(app), name=f"run_test {app}")
+        app_task = asyncio.create_task(run_app(app), name=f"run_test {app}")
 
         # Wait until the app has performed all startup routines.
         await app_ready_event.wait()
@@ -1353,7 +1356,7 @@ async def run_auto_pilot(
 
                 pilot = Pilot(app)
                 active_message_pump.set(self)
-                auto_pilot_task = create_task(
+                auto_pilot_task = asyncio.create_task(
                     run_auto_pilot(auto_pilot, pilot), name=repr(pilot)
                 )
 
@@ -2098,6 +2101,8 @@ def _handle_exception(self, error: Exception) -> None:
 
     def _fatal_error(self) -> None:
         """Exits the app after an unhandled exception."""
+        from rich.traceback import Traceback
+
         self.bell()
         traceback = Traceback(
             show_locals=True, width=None, locals_max_length=5, suppress=[rich]
@@ -2912,7 +2917,7 @@ async def prune_widgets_task(
         removed_widgets = self._detach_from_dom(widgets)
 
         finished_event = asyncio.Event()
-        remove_task = create_task(
+        remove_task = asyncio.create_task(
             prune_widgets_task(removed_widgets, finished_event), name="prune nodes"
         )
 

src/textual/command.py

@@ -7,7 +7,15 @@
 from __future__ import annotations
 
 from abc import ABC, abstractmethod
-from asyncio import CancelledError, Queue, Task, TimeoutError, wait, wait_for
+from asyncio import (
+    CancelledError,
+    Queue,
+    Task,
+    TimeoutError,
+    create_task,
+    wait,
+    wait_for,
+)
 from dataclasses import dataclass
 from functools import total_ordering
 from time import monotonic
@@ -19,11 +27,9 @@
 from rich.emoji import Emoji
 from rich.style import Style
 from rich.text import Text
-from rich.traceback import Traceback
 from typing_extensions import Final, TypeAlias
 
 from . import on, work
-from ._asyncio import create_task
 from .binding import Binding, BindingType
 from .containers import Horizontal, Vertical
 from .events import Click, Mount
@@ -165,6 +171,8 @@ async def post_init_task() -> None:
             try:
                 await self.startup()
             except Exception:
+                from rich.traceback import Traceback
+
                 self.app.log.error(Traceback())
             else:
                 self._init_success = True
@@ -211,6 +219,8 @@ async def _shutdown(self) -> None:
         try:
             await self.shutdown()
         except Exception:
+            from rich.traceback import Traceback
+
             self.app.log.error(Traceback())
 
     async def shutdown(self) -> None:
@@ -681,6 +691,8 @@ async def _search_for(self, search_value: str) -> AsyncGenerator[Hit, bool]:
             if search.done():
                 exception = search.exception()
                 if exception is not None:
+                    from rich.traceback import Traceback
+
                     self.log.error(
                         Traceback.from_exception(
                             type(exception), exception, exception.__traceback__

src/textual/css/_help_renderables.py

@@ -7,7 +7,6 @@
 from rich.highlighter import ReprHighlighter
 from rich.markup import render
 from rich.text import Text
-from rich.tree import Tree
 
 _highlighter = ReprHighlighter()
 
@@ -89,6 +88,8 @@ def __str__(self) -> str:
     def __rich_console__(
         self, console: Console, options: ConsoleOptions
     ) -> RenderResult:
+        from rich.tree import Tree
+
         tree = Tree(_markup_and_highlight(f"[b blue]{self.summary}"), guide_style="dim")
         if self.bullets is not None:
             for bullet in self.bullets:

src/textual/css/errors.py

@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 from rich.console import Console, ConsoleOptions, RenderResult
-from rich.traceback import Traceback
 
 from ._help_renderables import HelpText
 from .tokenizer import Token, TokenError
@@ -38,6 +37,8 @@ def __init__(self, *args: object, help_text: HelpText | None = None):
     def __rich_console__(
         self, console: Console, options: ConsoleOptions
     ) -> RenderResult:
+        from rich.traceback import Traceback
+
         yield Traceback.from_exception(type(self), self, self.__traceback__)
         if self.help_text is not None:
             yield ""

src/textual/css/stylesheet.py

@@ -12,7 +12,6 @@
 from rich.markup import render
 from rich.padding import Padding
 from rich.panel import Panel
-from rich.syntax import Syntax
 from rich.text import Text
 
 from .._cache import LRUCache
@@ -45,6 +44,8 @@ def __init__(self, rules: list[RuleSet]) -> None:
 
     @classmethod
     def _get_snippet(cls, code: str, line_no: int) -> RenderableType:
+        from rich.syntax import Syntax
+
         syntax = Syntax(
             code,
             lexer="scss",

src/textual/css/tokenizer.py

@@ -8,7 +8,6 @@
 from rich.highlighter import ReprHighlighter
 from rich.padding import Padding
 from rich.panel import Panel
-from rich.syntax import Syntax
 from rich.text import Text
 
 from ..suggestions import get_suggestion
@@ -51,6 +50,8 @@ def _get_snippet(self) -> Panel:
         Returns:
             A renderable.
         """
+        from rich.syntax import Syntax
+
         line_no = self.start[0]
         # TODO: Highlight column number
         syntax = Syntax(

src/textual/drivers/linux_driver.py

@@ -12,7 +12,6 @@
 from typing import TYPE_CHECKING, Any
 
 import rich.repr
-import rich.traceback
 
 from .. import events
 from .._xterm_parser import XTermParser
@@ -242,6 +241,8 @@ def _run_input_thread(self) -> None:
         try:
             self.run_input_thread()
         except BaseException as error:
+            import rich.traceback
+
             self._app.call_later(
                 self._app.panic,
                 rich.traceback.Traceback(),

src/textual/message_pump.py

@@ -12,14 +12,13 @@
 import asyncio
 import inspect
 import threading
-from asyncio import CancelledError, Queue, QueueEmpty, Task
+from asyncio import CancelledError, Queue, QueueEmpty, Task, create_task
 from contextlib import contextmanager
 from functools import partial
 from typing import TYPE_CHECKING, Any, Awaitable, Callable, Generator, Iterable, cast
 from weakref import WeakSet
 
 from . import Logger, events, log, messages
-from ._asyncio import create_task
 from ._callback import invoke
 from ._context import NoActiveAppError, active_app, active_message_pump
 from ._context import message_hook as message_hook_context_var

src/textual/timer.py

@@ -7,13 +7,12 @@
 from __future__ import annotations
 
 import weakref
-from asyncio import CancelledError, Event, Task
+from asyncio import CancelledError, Event, Task, create_task
 from typing import Any, Awaitable, Callable, Union
 
 from rich.repr import Result, rich_repr
 
 from . import _time, events
-from ._asyncio import create_task
 from ._callback import invoke
 from ._context import active_app
 from ._time import sleep

src/textual/widget.py

@@ -4,7 +4,7 @@
 
 from __future__ import annotations
 
-from asyncio import wait
+from asyncio import create_task, wait
 from collections import Counter
 from fractions import Fraction
 from itertools import islice
@@ -37,13 +37,11 @@
 from rich.segment import Segment
 from rich.style import Style
 from rich.text import Text
-from rich.traceback import Traceback
 from typing_extensions import Self
 
 from . import constants, errors, events, messages
 from ._animator import DEFAULT_EASING, Animatable, BoundAnimator, EasingFunction
 from ._arrange import DockArrangeResult, arrange
-from ._asyncio import create_task
 from ._cache import FIFOCache
 from ._compose import compose
 from ._context import NoActiveAppError, active_app
@@ -3305,6 +3303,8 @@ async def _on_compose(self) -> None:
                 f"{self!r} compose() method returned an invalid result; {error}"
             ) from error
         except Exception:
+            from rich.traceback import Traceback
+
             self.app.panic(Traceback())
         else:
             self._extend_compose(widgets)

src/textual/widgets/_markdown.py

@@ -7,7 +7,6 @@
 from markdown_it.token import Token
 from rich import box
 from rich.style import Style
-from rich.syntax import Syntax
 from rich.table import Table
 from rich.text import Text
 from typing_extensions import TypeAlias
@@ -503,6 +502,8 @@ def __init__(self, markdown: Markdown, code: str, lexer: str) -> None:
         super().__init__(markdown)
 
     def compose(self) -> ComposeResult:
+        from rich.syntax import Syntax
+
         yield Static(
             Syntax(
                 self.code,

src/textual/worker.py

@@ -21,7 +21,6 @@
 )
 
 import rich.repr
-from rich.traceback import Traceback
 from typing_extensions import TypeAlias
 
 from .message import Message
@@ -369,6 +368,8 @@ async def _run(self, app: App) -> None:
             self.state = WorkerState.ERROR
             self._error = error
             app.log.worker(self, "failed", repr(error))
+            from rich.traceback import Traceback
+
             app.log.worker(Traceback())
             if self.exit_on_error:
                 app._fatal_error()