progress.py

import sys
from abc import ABC, abstractmethod
from collections import deque
from collections.abc import Sized
from dataclasses import dataclass, field
from datetime import timedelta
from math import ceil
from threading import Event, RLock, Thread
from typing import (
    Any,
    Callable,
    Deque,
    Dict,
    Iterable,
    List,
    NamedTuple,
    NewType,
    Optional,
    Sequence,
    Tuple,
    TypeVar,
    Union,
)

from . import filesize, get_console
from .console import (
    Console,
    JustifyMethod,
    RenderableType,
    RenderGroup,
)
from .jupyter import JupyterMixin
from .highlighter import Highlighter
from .live import Live
from .progress_bar import ProgressBar
from .spinner import Spinner
from .style import StyleType
from .table import Column, Table
from .text import Text, TextType

TaskID = NewType("TaskID", int)

ProgressType = TypeVar("ProgressType")

GetTimeCallable = Callable[[], float]


class _TrackThread(Thread):
    """A thread to periodically update progress."""

    def __init__(self, progress: "Progress", task_id: "TaskID", update_period: float):
        self.progress = progress
        self.task_id = task_id
        self.update_period = update_period
        self.done = Event()

        self.completed = 0
        super().__init__()

    def run(self) -> None:
        task_id = self.task_id
        advance = self.progress.advance
        update_period = self.update_period
        last_completed = 0
        wait = self.done.wait
        while not wait(update_period):
            completed = self.completed
            if last_completed != completed:
                advance(task_id, completed - last_completed)
                last_completed = completed

        self.progress.update(self.task_id, completed=self.completed, refresh=True)

    def __enter__(self) -> "_TrackThread":
        self.start()
        return self

    def __exit__(self, exc_type, exc_val, exc_tb) -> None:
        self.done.set()
        self.join()


def track(
    sequence: Union[Sequence[ProgressType], Iterable[ProgressType]],
    description="Working...",
    total: Optional[float] = None,
    auto_refresh=True,
    console: Optional[Console] = None,
    transient: bool = False,
    get_time: Callable[[], float] = None,
    refresh_per_second: float = 10,
    style: StyleType = "bar.back",
    complete_style: StyleType = "bar.complete",
    finished_style: StyleType = "bar.finished",
    pulse_style: StyleType = "bar.pulse",
    update_period: float = 0.1,
    disable: bool = False,
) -> Iterable[ProgressType]:
    """Track progress by iterating over a sequence.

    Args:
        sequence (Iterable[ProgressType]): A sequence (must support "len") you wish to iterate over.
        description (str, optional): Description of task show next to progress bar. Defaults to "Working".
        total: (float, optional): Total number of steps. Default is len(sequence).
        auto_refresh (bool, optional): Automatic refresh, disable to force a refresh after each iteration. Default is True.
        transient: (bool, optional): Clear the progress on exit. Defaults to False.
        console (Console, optional): Console to write to. Default creates internal Console instance.
        refresh_per_second (float): Number of times per second to refresh the progress information. Defaults to 10.
        style (StyleType, optional): Style for the bar background. Defaults to "bar.back".
        complete_style (StyleType, optional): Style for the completed bar. Defaults to "bar.complete".
        finished_style (StyleType, optional): Style for a finished bar. Defaults to "bar.done".
        pulse_style (StyleType, optional): Style for pulsing bars. Defaults to "bar.pulse".
        update_period (float, optional): Minimum time (in seconds) between calls to update(). Defaults to 0.1.
        disable (bool, optional): Disable display of progress.
    Returns:
        Iterable[ProgressType]: An iterable of the values in the sequence.

    """

    columns: List["ProgressColumn"] = (
        [TextColumn("[progress.description]{task.description}")] if description else []
    )
    columns.extend(
        (
            BarColumn(
                style=style,
                complete_style=complete_style,
                finished_style=finished_style,
                pulse_style=pulse_style,
            ),
            TextColumn("[progress.percentage]{task.percentage:>3.0f}%"),
            TimeRemainingColumn(),
        )
    )
    progress = Progress(
        *columns,
        auto_refresh=auto_refresh,
        console=console,
        transient=transient,
        get_time=get_time,
        refresh_per_second=refresh_per_second or 10,
        disable=disable,
    )

    with progress:
        yield from progress.track(
            sequence, total=total, description=description, update_period=update_period
        )


class ProgressColumn(ABC):
    """Base class for a widget to use in progress display."""

    max_refresh: Optional[float] = None

    def __init__(self, table_column: Column = None) -> None:
        self._table_column = table_column
        self._renderable_cache: Dict[TaskID, Tuple[float, RenderableType]] = {}
        self._update_time: Optional[float] = None

    def get_table_column(self) -> Column:
        """Get a table column, used to build tasks table."""
        return self._table_column or Column()

    def __call__(self, task: "Task") -> RenderableType:
        """Called by the Progress object to return a renderable for the given task.

        Args:
            task (Task): An object containing information regarding the task.

        Returns:
            RenderableType: Anything renderable (including str).
        """
        current_time = task.get_time()  # type: ignore
        if self.max_refresh is not None and not task.completed:
            try:
                timestamp, renderable = self._renderable_cache[task.id]
            except KeyError:
                pass
            else:
                if timestamp + self.max_refresh > current_time:
                    return renderable

        renderable = self.render(task)
        self._renderable_cache[task.id] = (current_time, renderable)
        return renderable

    @abstractmethod
    def render(self, task: "Task") -> RenderableType:
        """Should return a renderable object."""


class RenderableColumn(ProgressColumn):
    """A column to insert an arbitrary column.

    Args:
        renderable (RenderableType, optional): Any renderable. Defaults to empty string.
    """

    def __init__(self, renderable: RenderableType = "", *, table_column: Column = None):
        self.renderable = renderable
        super().__init__(table_column=table_column)

    def render(self, task: "Task") -> RenderableType:
        return self.renderable


class SpinnerColumn(ProgressColumn):
    """A column with a 'spinner' animation.

    Args:
        spinner_name (str, optional): Name of spinner animation. Defaults to "dots".
        style (StyleType, optional): Style of spinner. Defaults to "progress.spinner".
        speed (float, optional): Speed factor of spinner. Defaults to 1.0.
        finished_text (TextType, optional): Text used when task is finished. Defaults to " ".
    """

    def __init__(
        self,
        spinner_name: str = "dots",
        style: Optional[StyleType] = "progress.spinner",
        speed: float = 1.0,
        finished_text: TextType = " ",
        table_column: Column = None,
    ):
        self.spinner = Spinner(spinner_name, style=style, speed=speed)
        self.finished_text = (
            Text.from_markup(finished_text)
            if isinstance(finished_text, str)
            else finished_text
        )
        super().__init__(table_column=table_column)

    def set_spinner(
        self,
        spinner_name: str,
        spinner_style: Optional[StyleType] = "progress.spinner",
        speed: float = 1.0,
    ):
        """Set a new spinner.

        Args:
            spinner_name (str): Spinner name, see python -m rich.spinner.
            spinner_style (Optional[StyleType], optional): Spinner style. Defaults to "progress.spinner".
            speed (float, optional): Speed factor of spinner. Defaults to 1.0.
        """
        self.spinner = Spinner(spinner_name, style=spinner_style, speed=speed)

    def render(self, task: "Task") -> Text:
        text = (
            self.finished_text
            if task.finished
            else self.spinner.render(task.get_time())
        )
        return text


class TextColumn(ProgressColumn):
    """A column containing text."""

    def __init__(
        self,
        text_format: str,
        style: StyleType = "none",
        justify: JustifyMethod = "left",
        markup: bool = True,
        highlighter: Highlighter = None,
        table_column: Column = None,
    ) -> None:
        self.text_format = text_format
        self.justify = justify
        self.style = style
        self.markup = markup
        self.highlighter = highlighter
        super().__init__(table_column=table_column or Column(no_wrap=True))

    def render(self, task: "Task") -> Text:
        _text = self.text_format.format(task=task)
        if self.markup:
            text = Text.from_markup(_text, style=self.style, justify=self.justify)
        else:
            text = Text(_text, style=self.style, justify=self.justify)
        if self.highlighter:
            self.highlighter.highlight(text)
        return text


class BarColumn(ProgressColumn):
    """Renders a visual progress bar.

    Args:
        bar_width (Optional[int], optional): Width of bar or None for full width. Defaults to 40.
        style (StyleType, optional): Style for the bar background. Defaults to "bar.back".
        complete_style (StyleType, optional): Style for the completed bar. Defaults to "bar.complete".
        finished_style (StyleType, optional): Style for a finished bar. Defaults to "bar.done".
        pulse_style (StyleType, optional): Style for pulsing bars. Defaults to "bar.pulse".
    """

    def __init__(
        self,
        bar_width: Optional[int] = 40,
        style: StyleType = "bar.back",
        complete_style: StyleType = "bar.complete",
        finished_style: StyleType = "bar.finished",
        pulse_style: StyleType = "bar.pulse",
        table_column: Column = None,
    ) -> None:
        self.bar_width = bar_width
        self.style = style
        self.complete_style = complete_style
        self.finished_style = finished_style
        self.pulse_style = pulse_style
        super().__init__(table_column=table_column)

    def render(self, task: "Task") -> ProgressBar:
        """Gets a progress bar widget for a task."""
        return ProgressBar(
            total=max(0, task.total),
            completed=max(0, task.completed),
            width=None if self.bar_width is None else max(1, self.bar_width),
            pulse=not task.started,
            animation_time=task.get_time(),
            style=self.style,
            complete_style=self.complete_style,
            finished_style=self.finished_style,
            pulse_style=self.pulse_style,
        )


class TimeElapsedColumn(ProgressColumn):
    """Renders time elapsed."""

    def render(self, task: "Task") -> Text:
        """Show time remaining."""
        elapsed = task.finished_time if task.finished else task.elapsed
        if elapsed is None:
            return Text("-:--:--", style="progress.elapsed")
        delta = timedelta(seconds=int(elapsed))
        return Text(str(delta), style="progress.elapsed")


class TimeRemainingColumn(ProgressColumn):
    """Renders estimated time remaining."""

    # Only refresh twice a second to prevent jitter
    max_refresh = 0.5

    def render(self, task: "Task") -> Text:
        """Show time remaining."""
        remaining = task.time_remaining
        if remaining is None:
            return Text("-:--:--", style="progress.remaining")
        remaining_delta = timedelta(seconds=int(remaining))
        return Text(str(remaining_delta), style="progress.remaining")


class FileSizeColumn(ProgressColumn):
    """Renders completed filesize."""

    def render(self, task: "Task") -> Text:
        """Show data completed."""
        data_size = filesize.decimal(int(task.completed))
        return Text(data_size, style="progress.filesize")


class TotalFileSizeColumn(ProgressColumn):
    """Renders total filesize."""

    def render(self, task: "Task") -> Text:
        """Show data completed."""
        data_size = filesize.decimal(int(task.total))
        return Text(data_size, style="progress.filesize.total")


class DownloadColumn(ProgressColumn):
    """Renders file size downloaded and total, e.g. '0.5/2.3 GB'.

    Args:
        binary_units (bool, optional): Use binary units, KiB, MiB etc. Defaults to False.
    """

    def __init__(self, binary_units: bool = False, table_column: Column = None) -> None:
        self.binary_units = binary_units
        super().__init__(table_column=table_column)

    def render(self, task: "Task") -> Text:
        """Calculate common unit for completed and total."""
        completed = int(task.completed)
        total = int(task.total)
        if self.binary_units:
            unit, suffix = filesize.pick_unit_and_suffix(
                total,
                ["bytes", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB"],
                1024,
            )
        else:
            unit, suffix = filesize.pick_unit_and_suffix(
                total, ["bytes", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"], 1000
            )
        completed_ratio = completed / unit
        total_ratio = total / unit
        precision = 0 if unit == 1 else 1
        completed_str = f"{completed_ratio:,.{precision}f}"
        total_str = f"{total_ratio:,.{precision}f}"
        download_status = f"{completed_str}/{total_str} {suffix}"
        download_text = Text(download_status, style="progress.download")
        return download_text


class TransferSpeedColumn(ProgressColumn):
    """Renders human readable transfer speed."""

    def render(self, task: "Task") -> Text:
        """Show data transfer speed."""
        speed = task.finished_speed or task.speed
        if speed is None:
            return Text("?", style="progress.data.speed")
        data_speed = filesize.decimal(int(speed))
        return Text(f"{data_speed}/s", style="progress.data.speed")


class ProgressSample(NamedTuple):
    """Sample of progress for a given time."""

    timestamp: float
    """Timestamp of sample."""
    completed: float
    """Number of steps completed."""


@dataclass
class Task:
    """Information regarding a progress task.

    This object should be considered read-only outside of the :class:`~Progress` class.

    """

    id: TaskID
    """Task ID associated with this task (used in Progress methods)."""

    description: str
    """str: Description of the task."""

    total: float
    """str: Total number of steps in this task."""

    completed: float
    """float: Number of steps completed"""

    _get_time: GetTimeCallable
    """Callable to get the current time."""

    finished_time: Optional[float] = None
    """float: Time task was finished."""

    visible: bool = True
    """bool: Indicates if this task is visible in the progress display."""

    fields: Dict[str, Any] = field(default_factory=dict)
    """dict: Arbitrary fields passed in via Progress.update."""

    start_time: Optional[float] = field(default=None, init=False, repr=False)
    """Optional[float]: Time this task was started, or None if not started."""

    stop_time: Optional[float] = field(default=None, init=False, repr=False)
    """Optional[float]: Time this task was stopped, or None if not stopped."""

    finished_speed: Optional[float] = None
    """Optional[float]: The last speed for a finshed task."""

    _progress: Deque[ProgressSample] = field(
        default_factory=deque, init=False, repr=False
    )

    _lock: RLock = field(repr=False, default_factory=RLock)
    """Thread lock."""

    def get_time(self) -> float:
        """float: Get the current time, in seconds."""
        return self._get_time()  # type: ignore

    @property
    def started(self) -> bool:
        """bool: Check if the task as started."""
        return self.start_time is not None

    @property
    def remaining(self) -> float:
        """float: Get the number of steps remaining."""
        return self.total - self.completed

    @property
    def elapsed(self) -> Optional[float]:
        """Optional[float]: Time elapsed since task was started, or ``None`` if the task hasn't started."""
        if self.start_time is None:
            return None
        if self.stop_time is not None:
            return self.stop_time - self.start_time
        return self.get_time() - self.start_time

    @property
    def finished(self) -> bool:
        """Check if the task has finished."""
        return self.finished_time is not None

    @property
    def percentage(self) -> float:
        """float: Get progress of task as a percentage."""
        if not self.total:
            return 0.0
        completed = (self.completed / self.total) * 100.0
        completed = min(100.0, max(0.0, completed))
        return completed

    @property
    def speed(self) -> Optional[float]:
        """Optional[float]: Get the estimated speed in steps per second."""
        if self.start_time is None:
            return None
        with self._lock:
            progress = self._progress
            if not progress:
                return None
            total_time = progress[-1].timestamp - progress[0].timestamp
            if total_time == 0:
                return None
            iter_progress = iter(progress)
            next(iter_progress)
            total_completed = sum(sample.completed for sample in iter_progress)
            speed = total_completed / total_time
            return speed

    @property
    def time_remaining(self) -> Optional[float]:
        """Optional[float]: Get estimated time to completion, or ``None`` if no data."""
        if self.finished:
            return 0.0
        speed = self.speed
        if not speed:
            return None
        estimate = ceil(self.remaining / speed)
        return estimate

    def _reset(self) -> None:
        """Reset progress."""
        self._progress.clear()
        self.finished_time = None
        self.finished_speed = None


class Progress(JupyterMixin):
    """Renders an auto-updating progress bar(s).

    Args:
        console (Console, optional): Optional Console instance. Default will an internal Console instance writing to stdout.
        auto_refresh (bool, optional): Enable auto refresh. If disabled, you will need to call `refresh()`.
        refresh_per_second (Optional[float], optional): Number of times per second to refresh the progress information or None to use default (10). Defaults to None.
        speed_estimate_period: (float, optional): Period (in seconds) used to calculate the speed estimate. Defaults to 30.
        transient: (bool, optional): Clear the progress on exit. Defaults to False.
        redirect_stdout: (bool, optional): Enable redirection of stdout, so ``print`` may be used. Defaults to True.
        redirect_stderr: (bool, optional): Enable redirection of stderr. Defaults to True.
        get_time: (Callable, optional): A callable that gets the current time, or None to use Console.get_time. Defaults to None.
        disable (bool, optional): Disable progress display. Defaults to False
        expand (bool, optional): Expand tasks table to fit width. Defaults to False.
    """

    def __init__(
        self,
        *columns: Union[str, ProgressColumn],
        console: Console = None,
        auto_refresh: bool = True,
        refresh_per_second: float = 10,
        speed_estimate_period: float = 30.0,
        transient: bool = False,
        redirect_stdout: bool = True,
        redirect_stderr: bool = True,
        get_time: GetTimeCallable = None,
        disable: bool = False,
        expand: bool = False,
    ) -> None:
        assert (
            refresh_per_second is None or refresh_per_second > 0  # type: ignore
        ), "refresh_per_second must be > 0"
        self._lock = RLock()
        self.columns = columns or (
            TextColumn("[progress.description]{task.description}"),
            BarColumn(),
            TextColumn("[progress.percentage]{task.percentage:>3.0f}%"),
            TimeRemainingColumn(),
        )
        self.speed_estimate_period = speed_estimate_period

        self.disable = disable
        self.expand = expand
        self._tasks: Dict[TaskID, Task] = {}
        self._task_index: TaskID = TaskID(0)
        self.live = Live(
            console=console or get_console(),
            auto_refresh=auto_refresh,
            refresh_per_second=refresh_per_second,
            transient=transient,
            redirect_stdout=redirect_stdout,
            redirect_stderr=redirect_stderr,
            get_renderable=self.get_renderable,
        )
        self.get_time = get_time or self.console.get_time
        self.print = self.console.print
        self.log = self.console.log

    @property
    def console(self) -> Console:
        return self.live.console

    @property
    def tasks(self) -> List[Task]:
        """Get a list of Task instances."""
        with self._lock:
            return list(self._tasks.values())

    @property
    def task_ids(self) -> List[TaskID]:
        """A list of task IDs."""
        with self._lock:
            return list(self._tasks.keys())

    @property
    def finished(self) -> bool:
        """Check if all tasks have been completed."""
        with self._lock:
            if not self._tasks:
                return True
            return all(task.finished for task in self._tasks.values())

    def start(self) -> None:
        """Start the progress display."""
        if not self.disable:
            self.live.start(refresh=True)

    def stop(self) -> None:
        """Stop the progress display."""
        self.live.stop()

    def __enter__(self) -> "Progress":
        self.start()
        return self

    def __exit__(self, exc_type, exc_val, exc_tb) -> None:
        self.stop()

    def track(
        self,
        sequence: Union[Iterable[ProgressType], Sequence[ProgressType]],
        total: Optional[float] = None,
        task_id: Optional[TaskID] = None,
        description="Working...",
        update_period: float = 0.1,
    ) -> Iterable[ProgressType]:
        """Track progress by iterating over a sequence.

        Args:
            sequence (Sequence[ProgressType]): A sequence of values you want to iterate over and track progress.
            total: (float, optional): Total number of steps. Default is len(sequence).
            task_id: (TaskID): Task to track. Default is new task.
            description: (str, optional): Description of task, if new task is created.
            update_period (float, optional): Minimum time (in seconds) between calls to update(). Defaults to 0.1.

        Returns:
            Iterable[ProgressType]: An iterable of values taken from the provided sequence.
        """

        if total is None:
            if isinstance(sequence, Sized):
                task_total = float(len(sequence))
            else:
                raise ValueError(
                    f"unable to get size of {sequence!r}, please specify 'total'"
                )
        else:
            task_total = total

        if task_id is None:
            task_id = self.add_task(description, total=task_total)
        else:
            self.update(task_id, total=task_total)

        if self.live.auto_refresh:
            with _TrackThread(self, task_id, update_period) as track_thread:
                for value in sequence:
                    yield value
                    track_thread.completed += 1
        else:
            advance = self.advance
            refresh = self.refresh
            for value in sequence:
                yield value
                advance(task_id, 1)
                refresh()

    def start_task(self, task_id: TaskID) -> None:
        """Start a task.

        Starts a task (used when calculating elapsed time). You may need to call this manually,
        if you called ``add_task`` with ``start=False``.

        Args:
            task_id (TaskID): ID of task.
        """
        with self._lock:
            task = self._tasks[task_id]
            if task.start_time is None:
                task.start_time = self.get_time()

    def stop_task(self, task_id: TaskID) -> None:
        """Stop a task.

        This will freeze the elapsed time on the task.

        Args:
            task_id (TaskID): ID of task.
        """
        with self._lock:
            task = self._tasks[task_id]
            current_time = self.get_time()
            if task.start_time is None:
                task.start_time = current_time
            task.stop_time = current_time

    def update(
        self,
        task_id: TaskID,
        *,
        total: Optional[float] = None,
        completed: float = None,
        advance: float = None,
        description: str = None,
        visible: bool = None,
        refresh: bool = False,
        **fields: Any,
    ) -> None:
        """Update information associated with a task.

        Args:
            task_id (TaskID): Task id (returned by add_task).
            total (float, optional): Updates task.total if not None.
            completed (float, optional): Updates task.completed if not None.
            advance (float, optional): Add a value to task.completed if not None.
            description (str, optional): Change task description if not None.
            visible (bool, optional): Set visible flag if not None.
            refresh (bool): Force a refresh of progress information. Default is False.
            **fields (Any): Additional data fields required for rendering.
        """
        with self._lock:
            task = self._tasks[task_id]
            completed_start = task.completed

            if total is not None:
                task.total = total
                task._reset()
            if advance is not None:
                task.completed += advance
            if completed is not None:
                task.completed = completed
            if description is not None:
                task.description = description
            if visible is not None:
                task.visible = visible
            task.fields.update(fields)
            update_completed = task.completed - completed_start

            current_time = self.get_time()
            old_sample_time = current_time - self.speed_estimate_period
            _progress = task._progress

            popleft = _progress.popleft
            while _progress and _progress[0].timestamp < old_sample_time:
                popleft()
            while len(_progress) > 1000:
                popleft()
            if update_completed > 0:
                _progress.append(ProgressSample(current_time, update_completed))
            if task.completed >= task.total and task.finished_time is None:
                task.finished_time = task.elapsed

        if refresh:
            self.refresh()

    def reset(
        self,
        task_id: TaskID,
        *,
        start: bool = True,
        total: Optional[float] = None,
        completed: int = 0,
        visible: Optional[bool] = None,
        description: Optional[str] = None,
        **fields: Any,
    ) -> None:
        """Reset a task so completed is 0 and the clock is reset.

        Args:
            task_id (TaskID): ID of task.
            start (bool, optional): Start the task after reset. Defaults to True.
            total (float, optional): New total steps in task, or None to use current total. Defaults to None.
            completed (int, optional): Number of steps completed. Defaults to 0.
            **fields (str): Additional data fields required for rendering.
        """
        current_time = self.get_time()
        with self._lock:
            task = self._tasks[task_id]
            task._reset()
            task.start_time = current_time if start else None
            if total is not None:
                task.total = total
            task.completed = completed
            if visible is not None:
                task.visible = visible
            if fields:
                task.fields = fields
            if description is not None:
                task.description = description
            task.finished_time = None
        self.refresh()

    def advance(self, task_id: TaskID, advance: float = 1) -> None:
        """Advance task by a number of steps.

        Args:
            task_id (TaskID): ID of task.
            advance (float): Number of steps to advance. Default is 1.
        """
        current_time = self.get_time()
        with self._lock:
            task = self._tasks[task_id]
            completed_start = task.completed
            task.completed += advance
            update_completed = task.completed - completed_start
            old_sample_time = current_time - self.speed_estimate_period
            _progress = task._progress

            popleft = _progress.popleft
            while _progress and _progress[0].timestamp < old_sample_time:
                popleft()
            while len(_progress) > 1000:
                popleft()
            _progress.append(ProgressSample(current_time, update_completed))
            if task.completed >= task.total and task.finished_time is None:
                task.finished_time = task.elapsed
                task.finished_speed = task.speed

    def refresh(self) -> None:
        """Refresh (render) the progress information."""
        if not self.disable:
            self.live.refresh()

    def get_renderable(self) -> RenderableType:
        """Get a renderable for the progress display."""
        renderable = RenderGroup(*self.get_renderables())
        return renderable

    def get_renderables(self) -> Iterable[RenderableType]:
        """Get a number of renderables for the progress display."""
        table = self.make_tasks_table(self.tasks)
        yield table

    def make_tasks_table(self, tasks: Iterable[Task]) -> Table:
        """Get a table to render the Progress display.

        Args:
            tasks (Iterable[Task]): An iterable of Task instances, one per row of the table.

        Returns:
            Table: A table instance.
        """

        table_columns = (
            (
                Column(no_wrap=True)
                if isinstance(_column, str)
                else _column.get_table_column().copy()
            )
            for _column in self.columns
        )
        table = Table.grid(*table_columns, padding=(0, 1), expand=self.expand)

        for task in tasks:
            if task.visible:
                table.add_row(
                    *(
                        (
                            column.format(task=task)
                            if isinstance(column, str)
                            else column(task)
                        )
                        for column in self.columns
                    )
                )
        return table

    def __rich__(self) -> RenderableType:
        """Makes the Progress class itself renderable."""
        return self.get_renderable()

    def add_task(
        self,
        description: str,
        start: bool = True,
        total: float = 100.0,
        completed: int = 0,
        visible: bool = True,
        **fields: Any,
    ) -> TaskID:
        """Add a new 'task' to the Progress display.

        Args:
            description (str): A description of the task.
            start (bool, optional): Start the task immediately (to calculate elapsed time). If set to False,
                you will need to call `start` manually. Defaults to True.
            total (float, optional): Number of total steps in the progress if know. Defaults to 100.
            completed (int, optional): Number of steps completed so far.. Defaults to 0.
            visible (bool, optional): Enable display of the task. Defaults to True.
            **fields (str): Additional data fields required for rendering.

        Returns:
            TaskID: An ID you can use when calling `update`.
        """
        with self._lock:
            task = Task(
                self._task_index,
                description,
                total,
                completed,
                visible=visible,
                fields=fields,
                _get_time=self.get_time,
                _lock=self._lock,
            )
            self._tasks[self._task_index] = task
            if start:
                self.start_task(self._task_index)
            new_task_index = self._task_index
            self._task_index = TaskID(int(self._task_index) + 1)
        self.refresh()
        return new_task_index

    def remove_task(self, task_id: TaskID) -> None:
        """Delete a task if it exists.

        Args:
            task_id (TaskID): A task ID.

        """
        with self._lock:
            del self._tasks[task_id]


if __name__ == "__main__":  # pragma: no coverage

    import random
    import time

    from .panel import Panel
    from .rule import Rule
    from .syntax import Syntax
    from .table import Table

    syntax = Syntax(
        '''def loop_last(values: Iterable[T]) -> Iterable[Tuple[bool, T]]:
    """Iterate and generate a tuple with a flag for last value."""
    iter_values = iter(values)
    try:
        previous_value = next(iter_values)
    except StopIteration:
        return
    for value in iter_values:
        yield False, previous_value
        previous_value = value
    yield True, previous_value''',
        "python",
        line_numbers=True,
    )

    table = Table("foo", "bar", "baz")
    table.add_row("1", "2", "3")

    progress_renderables = [
        "Text may be printed while the progress bars are rendering.",
        Panel("In fact, [i]any[/i] renderable will work"),
        "Such as [magenta]tables[/]...",
        table,
        "Pretty printed structures...",
        {"type": "example", "text": "Pretty printed"},
        "Syntax...",
        syntax,
        Rule("Give it a try!"),
    ]

    from itertools import cycle

    examples = cycle(progress_renderables)

    console = Console(record=True)

    with Progress(
        SpinnerColumn(),
        TextColumn("[progress.description]{task.description}"),
        BarColumn(),
        TextColumn("[progress.percentage]{task.percentage:>3.0f}%"),
        TimeRemainingColumn(),
        TimeElapsedColumn(),
        console=console,
        transient=True,
    ) as progress:

        task1 = progress.add_task("[red]Downloading", total=1000)
        task2 = progress.add_task("[green]Processing", total=1000)
        task3 = progress.add_task("[yellow]Thinking", total=1000, start=False)

        while not progress.finished:
            progress.update(task1, advance=0.5)
            progress.update(task2, advance=0.3)
            time.sleep(0.01)
            if random.randint(0, 100) < 1:
                progress.log(next(examples))