Source code for rich.segment

from enum import IntEnum
from functools import lru_cache
from itertools import filterfalse
from logging import getLogger
from operator import attrgetter
from typing import (
    TYPE_CHECKING,
    Dict,
    Iterable,
    List,
    NamedTuple,
    Optional,
    Sequence,
    Tuple,
    Type,
    Union,
)

from .cells import (
    _is_single_cell_widths,
    cached_cell_len,
    cell_len,
    get_character_cell_size,
    set_cell_size,
)
from .repr import Result, rich_repr
from .style import Style

if TYPE_CHECKING:
    from .console import Console, ConsoleOptions, RenderResult

log = getLogger("rich")


[docs]class ControlType(IntEnum): """Non-printable control codes which typically translate to ANSI codes.""" BELL = 1 CARRIAGE_RETURN = 2 HOME = 3 CLEAR = 4 SHOW_CURSOR = 5 HIDE_CURSOR = 6 ENABLE_ALT_SCREEN = 7 DISABLE_ALT_SCREEN = 8 CURSOR_UP = 9 CURSOR_DOWN = 10 CURSOR_FORWARD = 11 CURSOR_BACKWARD = 12 CURSOR_MOVE_TO_COLUMN = 13 CURSOR_MOVE_TO = 14 ERASE_IN_LINE = 15 SET_WINDOW_TITLE = 16
ControlCode = Union[ Tuple[ControlType], Tuple[ControlType, Union[int, str]], Tuple[ControlType, int, int], ]
[docs]@rich_repr() class Segment(NamedTuple): """A piece of text with associated style. Segments are produced by the Console render process and are ultimately converted in to strings to be written to the terminal. Args: text (str): A piece of text. style (:class:`~rich.style.Style`, optional): An optional style to apply to the text. control (Tuple[ControlCode], optional): Optional sequence of control codes. Attributes: cell_length (int): The cell length of this Segment. """ text: str style: Optional[Style] = None control: Optional[Sequence[ControlCode]] = None @property def cell_length(self) -> int: """The number of terminal cells required to display self.text. Returns: int: A number of cells. """ text, _style, control = self return 0 if control else cell_len(text) def __rich_repr__(self) -> Result: yield self.text if self.control is None: if self.style is not None: yield self.style else: yield self.style yield self.control def __bool__(self) -> bool: """Check if the segment contains text.""" return bool(self.text) @property def is_control(self) -> bool: """Check if the segment contains control codes.""" return self.control is not None @classmethod @lru_cache(1024 * 16) def _split_cells(cls, segment: "Segment", cut: int) -> Tuple["Segment", "Segment"]: text, style, control = segment _Segment = Segment cell_length = segment.cell_length if cut >= cell_length: return segment, _Segment("", style, control) cell_size = get_character_cell_size pos = int((cut / cell_length) * len(text)) before = text[:pos] cell_pos = cell_len(before) if cell_pos == cut: return ( _Segment(before, style, control), _Segment(text[pos:], style, control), ) while pos < len(text): char = text[pos] pos += 1 cell_pos += cell_size(char) before = text[:pos] if cell_pos == cut: return ( _Segment(before, style, control), _Segment(text[pos:], style, control), ) if cell_pos > cut: return ( _Segment(before[: pos - 1] + " ", style, control), _Segment(" " + text[pos:], style, control), ) raise AssertionError("Will never reach here")
[docs] def split_cells(self, cut: int) -> Tuple["Segment", "Segment"]: """Split segment in to two segments at the specified column. If the cut point falls in the middle of a 2-cell wide character then it is replaced by two spaces, to preserve the display width of the parent segment. Returns: Tuple[Segment, Segment]: Two segments. """ text, style, control = self if _is_single_cell_widths(text): # Fast path with all 1 cell characters if cut >= len(text): return self, Segment("", style, control) return ( Segment(text[:cut], style, control), Segment(text[cut:], style, control), ) return self._split_cells(self, cut)
[docs] @classmethod def line(cls) -> "Segment": """Make a new line segment.""" return cls("\n")
[docs] @classmethod def apply_style( cls, segments: Iterable["Segment"], style: Optional[Style] = None, post_style: Optional[Style] = None, ) -> Iterable["Segment"]: """Apply style(s) to an iterable of segments. Returns an iterable of segments where the style is replaced by ``style + segment.style + post_style``. Args: segments (Iterable[Segment]): Segments to process. style (Style, optional): Base style. Defaults to None. post_style (Style, optional): Style to apply on top of segment style. Defaults to None. Returns: Iterable[Segments]: A new iterable of segments (possibly the same iterable). """ result_segments = segments if style: apply = style.__add__ result_segments = ( cls(text, None if control else apply(_style), control) for text, _style, control in result_segments ) if post_style: result_segments = ( cls( text, ( None if control else (_style + post_style if _style else post_style) ), control, ) for text, _style, control in result_segments ) return result_segments
[docs] @classmethod def filter_control( cls, segments: Iterable["Segment"], is_control: bool = False ) -> Iterable["Segment"]: """Filter segments by ``is_control`` attribute. Args: segments (Iterable[Segment]): An iterable of Segment instances. is_control (bool, optional): is_control flag to match in search. Returns: Iterable[Segment]: And iterable of Segment instances. """ if is_control: return filter(attrgetter("control"), segments) else: return filterfalse(attrgetter("control"), segments)
[docs] @classmethod def split_lines(cls, segments: Iterable["Segment"]) -> Iterable[List["Segment"]]: """Split a sequence of segments in to a list of lines. Args: segments (Iterable[Segment]): Segments potentially containing line feeds. Yields: Iterable[List[Segment]]: Iterable of segment lists, one per line. """ line: List[Segment] = [] append = line.append for segment in segments: if "\n" in segment.text and not segment.control: text, style, _ = segment while text: _text, new_line, text = text.partition("\n") if _text: append(cls(_text, style)) if new_line: yield line line = [] append = line.append else: append(segment) if line: yield line
[docs] @classmethod def split_and_crop_lines( cls, segments: Iterable["Segment"], length: int, style: Optional[Style] = None, pad: bool = True, include_new_lines: bool = True, ) -> Iterable[List["Segment"]]: """Split segments in to lines, and crop lines greater than a given length. Args: segments (Iterable[Segment]): An iterable of segments, probably generated from console.render. length (int): Desired line length. style (Style, optional): Style to use for any padding. pad (bool): Enable padding of lines that are less than `length`. Returns: Iterable[List[Segment]]: An iterable of lines of segments. """ line: List[Segment] = [] append = line.append adjust_line_length = cls.adjust_line_length new_line_segment = cls("\n") for segment in segments: if "\n" in segment.text and not segment.control: text, segment_style, _ = segment while text: _text, new_line, text = text.partition("\n") if _text: append(cls(_text, segment_style)) if new_line: cropped_line = adjust_line_length( line, length, style=style, pad=pad ) if include_new_lines: cropped_line.append(new_line_segment) yield cropped_line del line[:] else: append(segment) if line: yield adjust_line_length(line, length, style=style, pad=pad)
[docs] @classmethod def adjust_line_length( cls, line: List["Segment"], length: int, style: Optional[Style] = None, pad: bool = True, ) -> List["Segment"]: """Adjust a line to a given width (cropping or padding as required). Args: segments (Iterable[Segment]): A list of segments in a single line. length (int): The desired width of the line. style (Style, optional): The style of padding if used (space on the end). Defaults to None. pad (bool, optional): Pad lines with spaces if they are shorter than `length`. Defaults to True. Returns: List[Segment]: A line of segments with the desired length. """ line_length = sum(segment.cell_length for segment in line) new_line: List[Segment] if line_length < length: if pad: new_line = line + [cls(" " * (length - line_length), style)] else: new_line = line[:] elif line_length > length: new_line = [] append = new_line.append line_length = 0 for segment in line: segment_length = segment.cell_length if line_length + segment_length < length or segment.control: append(segment) line_length += segment_length else: text, segment_style, _ = segment text = set_cell_size(text, length - line_length) append(cls(text, segment_style)) break else: new_line = line[:] return new_line
[docs] @classmethod def get_line_length(cls, line: List["Segment"]) -> int: """Get the length of list of segments. Args: line (List[Segment]): A line encoded as a list of Segments (assumes no '\\\\n' characters), Returns: int: The length of the line. """ _cell_len = cell_len return sum(_cell_len(segment.text) for segment in line)
[docs] @classmethod def get_shape(cls, lines: List[List["Segment"]]) -> Tuple[int, int]: """Get the shape (enclosing rectangle) of a list of lines. Args: lines (List[List[Segment]]): A list of lines (no '\\\\n' characters). Returns: Tuple[int, int]: Width and height in characters. """ get_line_length = cls.get_line_length max_width = max(get_line_length(line) for line in lines) if lines else 0 return (max_width, len(lines))
[docs] @classmethod def set_shape( cls, lines: List[List["Segment"]], width: int, height: Optional[int] = None, style: Optional[Style] = None, new_lines: bool = False, ) -> List[List["Segment"]]: """Set the shape of a list of lines (enclosing rectangle). Args: lines (List[List[Segment]]): A list of lines. width (int): Desired width. height (int, optional): Desired height or None for no change. style (Style, optional): Style of any padding added. new_lines (bool, optional): Padded lines should include "\n". Defaults to False. Returns: List[List[Segment]]: New list of lines. """ _height = height or len(lines) blank = ( [cls(" " * width + "\n", style)] if new_lines else [cls(" " * width, style)] ) adjust_line_length = cls.adjust_line_length shaped_lines = lines[:_height] shaped_lines[:] = [ adjust_line_length(line, width, style=style) for line in lines ] if len(shaped_lines) < _height: shaped_lines.extend([blank] * (_height - len(shaped_lines))) return shaped_lines
[docs] @classmethod def align_top( cls: Type["Segment"], lines: List[List["Segment"]], width: int, height: int, style: Style, new_lines: bool = False, ) -> List[List["Segment"]]: """Aligns lines to top (adds extra lines to bottom as required). Args: lines (List[List[Segment]]): A list of lines. width (int): Desired width. height (int, optional): Desired height or None for no change. style (Style): Style of any padding added. new_lines (bool, optional): Padded lines should include "\n". Defaults to False. Returns: List[List[Segment]]: New list of lines. """ extra_lines = height - len(lines) if not extra_lines: return lines[:] lines = lines[:height] blank = cls(" " * width + "\n", style) if new_lines else cls(" " * width, style) lines = lines + [[blank]] * extra_lines return lines
[docs] @classmethod def align_bottom( cls: Type["Segment"], lines: List[List["Segment"]], width: int, height: int, style: Style, new_lines: bool = False, ) -> List[List["Segment"]]: """Aligns render to bottom (adds extra lines above as required). Args: lines (List[List[Segment]]): A list of lines. width (int): Desired width. height (int, optional): Desired height or None for no change. style (Style): Style of any padding added. Defaults to None. new_lines (bool, optional): Padded lines should include "\n". Defaults to False. Returns: List[List[Segment]]: New list of lines. """ extra_lines = height - len(lines) if not extra_lines: return lines[:] lines = lines[:height] blank = cls(" " * width + "\n", style) if new_lines else cls(" " * width, style) lines = [[blank]] * extra_lines + lines return lines
[docs] @classmethod def align_middle( cls: Type["Segment"], lines: List[List["Segment"]], width: int, height: int, style: Style, new_lines: bool = False, ) -> List[List["Segment"]]: """Aligns lines to middle (adds extra lines to above and below as required). Args: lines (List[List[Segment]]): A list of lines. width (int): Desired width. height (int, optional): Desired height or None for no change. style (Style): Style of any padding added. new_lines (bool, optional): Padded lines should include "\n". Defaults to False. Returns: List[List[Segment]]: New list of lines. """ extra_lines = height - len(lines) if not extra_lines: return lines[:] lines = lines[:height] blank = cls(" " * width + "\n", style) if new_lines else cls(" " * width, style) top_lines = extra_lines // 2 bottom_lines = extra_lines - top_lines lines = [[blank]] * top_lines + lines + [[blank]] * bottom_lines return lines
[docs] @classmethod def simplify(cls, segments: Iterable["Segment"]) -> Iterable["Segment"]: """Simplify an iterable of segments by combining contiguous segments with the same style. Args: segments (Iterable[Segment]): An iterable of segments. Returns: Iterable[Segment]: A possibly smaller iterable of segments that will render the same way. """ iter_segments = iter(segments) try: last_segment = next(iter_segments) except StopIteration: return _Segment = Segment for segment in iter_segments: if last_segment.style == segment.style and not segment.control: last_segment = _Segment( last_segment.text + segment.text, last_segment.style ) else: yield last_segment last_segment = segment yield last_segment
[docs] @classmethod def strip_styles(cls, segments: Iterable["Segment"]) -> Iterable["Segment"]: """Remove all styles from an iterable of segments. Args: segments (Iterable[Segment]): An iterable segments. Yields: Segment: Segments with styles replace with None """ for text, _style, control in segments: yield cls(text, None, control)
[docs] @classmethod def remove_color(cls, segments: Iterable["Segment"]) -> Iterable["Segment"]: """Remove all color from an iterable of segments. Args: segments (Iterable[Segment]): An iterable segments. Yields: Segment: Segments with colorless style. """ cache: Dict[Style, Style] = {} for text, style, control in segments: if style: colorless_style = cache.get(style) if colorless_style is None: colorless_style = style.without_color cache[style] = colorless_style yield cls(text, colorless_style, control) else: yield cls(text, None, control)
[docs] @classmethod def divide( cls, segments: Iterable["Segment"], cuts: Iterable[int] ) -> Iterable[List["Segment"]]: """Divides an iterable of segments in to portions. Args: cuts (Iterable[int]): Cell positions where to divide. Yields: [Iterable[List[Segment]]]: An iterable of Segments in List. """ split_segments: List["Segment"] = [] add_segment = split_segments.append iter_cuts = iter(cuts) while True: cut = next(iter_cuts, -1) if cut == -1: return [] if cut != 0: break yield [] pos = 0 segments_clear = split_segments.clear segments_copy = split_segments.copy _cell_len = cached_cell_len for segment in segments: text, _style, control = segment while text: end_pos = pos if control else pos + _cell_len(text) if end_pos < cut: add_segment(segment) pos = end_pos break if end_pos == cut: add_segment(segment) yield segments_copy() segments_clear() pos = end_pos cut = next(iter_cuts, -1) if cut == -1: if split_segments: yield segments_copy() return break else: before, segment = segment.split_cells(cut - pos) text, _style, control = segment add_segment(before) yield segments_copy() segments_clear() pos = cut cut = next(iter_cuts, -1) if cut == -1: if split_segments: yield segments_copy() return yield segments_copy()
[docs]class Segments: """A simple renderable to render an iterable of segments. This class may be useful if you want to print segments outside of a __rich_console__ method. Args: segments (Iterable[Segment]): An iterable of segments. new_lines (bool, optional): Add new lines between segments. Defaults to False. """ def __init__(self, segments: Iterable[Segment], new_lines: bool = False) -> None: self.segments = list(segments) self.new_lines = new_lines def __rich_console__( self, console: "Console", options: "ConsoleOptions" ) -> "RenderResult": if self.new_lines: line = Segment.line() for segment in self.segments: yield segment yield line else: yield from self.segments
class SegmentLines: def __init__(self, lines: Iterable[List[Segment]], new_lines: bool = False) -> None: """A simple renderable containing a number of lines of segments. May be used as an intermediate in rendering process. Args: lines (Iterable[List[Segment]]): Lists of segments forming lines. new_lines (bool, optional): Insert new lines after each line. Defaults to False. """ self.lines = list(lines) self.new_lines = new_lines def __rich_console__( self, console: "Console", options: "ConsoleOptions" ) -> "RenderResult": if self.new_lines: new_line = Segment.line() for line in self.lines: yield from line yield new_line else: for line in self.lines: yield from line if __name__ == "__main__": # pragma: no cover from rich.console import Console from rich.syntax import Syntax from rich.text import Text code = """from rich.console import Console console = Console() text = Text.from_markup("Hello, [bold magenta]World[/]!") console.print(text)""" text = Text.from_markup("Hello, [bold magenta]World[/]!") console = Console() console.rule("rich.Segment") console.print( "A Segment is the last step in the Rich render process before generating text with ANSI codes." ) console.print("\nConsider the following code:\n") console.print(Syntax(code, "python", line_numbers=True)) console.print() console.print( "When you call [b]print()[/b], Rich [i]renders[/i] the object in to the the following:\n" ) fragments = list(console.render(text)) console.print(fragments) console.print() console.print("The Segments are then processed to produce the following output:\n") console.print(text) console.print( "\nYou will only need to know this if you are implementing your own Rich renderables." )