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import typing as t |
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from contextlib import contextmanager |
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from gettext import gettext as _ |
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from ._compat import term_len |
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from .parser import split_opt |
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FORCED_WIDTH: t.Optional[int] = None |
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def measure_table(rows: t.Iterable[t.Tuple[str, str]]) -> t.Tuple[int, ...]: |
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widths: t.Dict[int, int] = {} |
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for row in rows: |
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for idx, col in enumerate(row): |
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widths[idx] = max(widths.get(idx, 0), term_len(col)) |
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return tuple(y for x, y in sorted(widths.items())) |
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def iter_rows( |
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rows: t.Iterable[t.Tuple[str, str]], col_count: int |
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) -> t.Iterator[t.Tuple[str, ...]]: |
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for row in rows: |
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yield row + ("",) * (col_count - len(row)) |
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def wrap_text( |
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text: str, |
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width: int = 78, |
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initial_indent: str = "", |
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subsequent_indent: str = "", |
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preserve_paragraphs: bool = False, |
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) -> str: |
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"""A helper function that intelligently wraps text. By default, it |
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assumes that it operates on a single paragraph of text but if the |
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`preserve_paragraphs` parameter is provided it will intelligently |
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handle paragraphs (defined by two empty lines). |
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If paragraphs are handled, a paragraph can be prefixed with an empty |
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line containing the ``\\b`` character (``\\x08``) to indicate that |
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no rewrapping should happen in that block. |
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:param text: the text that should be rewrapped. |
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:param width: the maximum width for the text. |
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:param initial_indent: the initial indent that should be placed on the |
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first line as a string. |
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:param subsequent_indent: the indent string that should be placed on |
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each consecutive line. |
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:param preserve_paragraphs: if this flag is set then the wrapping will |
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intelligently handle paragraphs. |
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""" |
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from ._textwrap import TextWrapper |
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text = text.expandtabs() |
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wrapper = TextWrapper( |
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width, |
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initial_indent=initial_indent, |
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subsequent_indent=subsequent_indent, |
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replace_whitespace=False, |
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) |
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if not preserve_paragraphs: |
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return wrapper.fill(text) |
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p: t.List[t.Tuple[int, bool, str]] = [] |
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buf: t.List[str] = [] |
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indent = None |
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def _flush_par() -> None: |
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if not buf: |
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return |
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if buf[0].strip() == "\b": |
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p.append((indent or 0, True, "\n".join(buf[1:]))) |
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else: |
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p.append((indent or 0, False, " ".join(buf))) |
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del buf[:] |
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for line in text.splitlines(): |
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if not line: |
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_flush_par() |
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indent = None |
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else: |
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if indent is None: |
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orig_len = term_len(line) |
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line = line.lstrip() |
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indent = orig_len - term_len(line) |
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buf.append(line) |
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_flush_par() |
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rv = [] |
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for indent, raw, text in p: |
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with wrapper.extra_indent(" " * indent): |
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if raw: |
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rv.append(wrapper.indent_only(text)) |
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else: |
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rv.append(wrapper.fill(text)) |
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return "\n\n".join(rv) |
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class HelpFormatter: |
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"""This class helps with formatting text-based help pages. It's |
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usually just needed for very special internal cases, but it's also |
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exposed so that developers can write their own fancy outputs. |
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At present, it always writes into memory. |
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:param indent_increment: the additional increment for each level. |
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:param width: the width for the text. This defaults to the terminal |
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width clamped to a maximum of 78. |
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""" |
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def __init__( |
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self, |
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indent_increment: int = 2, |
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width: t.Optional[int] = None, |
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max_width: t.Optional[int] = None, |
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) -> None: |
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import shutil |
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self.indent_increment = indent_increment |
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if max_width is None: |
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max_width = 80 |
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if width is None: |
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width = FORCED_WIDTH |
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if width is None: |
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width = max(min(shutil.get_terminal_size().columns, max_width) - 2, 50) |
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self.width = width |
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self.current_indent = 0 |
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self.buffer: t.List[str] = [] |
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def write(self, string: str) -> None: |
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"""Writes a unicode string into the internal buffer.""" |
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self.buffer.append(string) |
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def indent(self) -> None: |
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"""Increases the indentation.""" |
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self.current_indent += self.indent_increment |
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def dedent(self) -> None: |
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"""Decreases the indentation.""" |
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self.current_indent -= self.indent_increment |
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def write_usage( |
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self, prog: str, args: str = "", prefix: t.Optional[str] = None |
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) -> None: |
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"""Writes a usage line into the buffer. |
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:param prog: the program name. |
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:param args: whitespace separated list of arguments. |
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:param prefix: The prefix for the first line. Defaults to |
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``"Usage: "``. |
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""" |
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if prefix is None: |
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prefix = f"{_('Usage:')} " |
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usage_prefix = f"{prefix:>{self.current_indent}}{prog} " |
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text_width = self.width - self.current_indent |
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if text_width >= (term_len(usage_prefix) + 20): |
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indent = " " * term_len(usage_prefix) |
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self.write( |
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wrap_text( |
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args, |
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text_width, |
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initial_indent=usage_prefix, |
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subsequent_indent=indent, |
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) |
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) |
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else: |
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self.write(usage_prefix) |
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self.write("\n") |
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indent = " " * (max(self.current_indent, term_len(prefix)) + 4) |
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self.write( |
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wrap_text( |
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args, text_width, initial_indent=indent, subsequent_indent=indent |
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) |
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) |
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self.write("\n") |
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def write_heading(self, heading: str) -> None: |
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"""Writes a heading into the buffer.""" |
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self.write(f"{'':>{self.current_indent}}{heading}:\n") |
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def write_paragraph(self) -> None: |
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"""Writes a paragraph into the buffer.""" |
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if self.buffer: |
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self.write("\n") |
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def write_text(self, text: str) -> None: |
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"""Writes re-indented text into the buffer. This rewraps and |
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preserves paragraphs. |
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""" |
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indent = " " * self.current_indent |
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self.write( |
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wrap_text( |
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text, |
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self.width, |
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initial_indent=indent, |
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subsequent_indent=indent, |
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preserve_paragraphs=True, |
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) |
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) |
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self.write("\n") |
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def write_dl( |
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self, |
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rows: t.Sequence[t.Tuple[str, str]], |
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col_max: int = 30, |
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col_spacing: int = 2, |
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) -> None: |
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"""Writes a definition list into the buffer. This is how options |
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and commands are usually formatted. |
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:param rows: a list of two item tuples for the terms and values. |
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:param col_max: the maximum width of the first column. |
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:param col_spacing: the number of spaces between the first and |
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second column. |
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""" |
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rows = list(rows) |
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widths = measure_table(rows) |
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if len(widths) != 2: |
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raise TypeError("Expected two columns for definition list") |
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first_col = min(widths[0], col_max) + col_spacing |
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for first, second in iter_rows(rows, len(widths)): |
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self.write(f"{'':>{self.current_indent}}{first}") |
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if not second: |
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self.write("\n") |
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continue |
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if term_len(first) <= first_col - col_spacing: |
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self.write(" " * (first_col - term_len(first))) |
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else: |
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self.write("\n") |
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self.write(" " * (first_col + self.current_indent)) |
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text_width = max(self.width - first_col - 2, 10) |
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wrapped_text = wrap_text(second, text_width, preserve_paragraphs=True) |
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lines = wrapped_text.splitlines() |
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if lines: |
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self.write(f"{lines[0]}\n") |
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for line in lines[1:]: |
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self.write(f"{'':>{first_col + self.current_indent}}{line}\n") |
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else: |
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self.write("\n") |
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@contextmanager |
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def section(self, name: str) -> t.Iterator[None]: |
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"""Helpful context manager that writes a paragraph, a heading, |
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and the indents. |
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:param name: the section name that is written as heading. |
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""" |
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self.write_paragraph() |
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self.write_heading(name) |
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self.indent() |
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try: |
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yield |
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finally: |
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self.dedent() |
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@contextmanager |
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def indentation(self) -> t.Iterator[None]: |
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"""A context manager that increases the indentation.""" |
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self.indent() |
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try: |
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yield |
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finally: |
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self.dedent() |
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def getvalue(self) -> str: |
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"""Returns the buffer contents.""" |
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return "".join(self.buffer) |
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def join_options(options: t.Sequence[str]) -> t.Tuple[str, bool]: |
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"""Given a list of option strings this joins them in the most appropriate |
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way and returns them in the form ``(formatted_string, |
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any_prefix_is_slash)`` where the second item in the tuple is a flag that |
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indicates if any of the option prefixes was a slash. |
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""" |
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rv = [] |
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any_prefix_is_slash = False |
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for opt in options: |
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prefix = split_opt(opt)[0] |
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if prefix == "/": |
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any_prefix_is_slash = True |
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rv.append((len(prefix), opt)) |
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rv.sort(key=lambda x: x[0]) |
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return ", ".join(x[1] for x in rv), any_prefix_is_slash |
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