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# Tables Extension for Python-Markdown | |
# ==================================== | |
# Added parsing of tables to Python-Markdown. | |
# See https://Python-Markdown.github.io/extensions/tables | |
# for documentation. | |
# Original code Copyright 2009 [Waylan Limberg](http://achinghead.com) | |
# All changes Copyright 2008-2014 The Python Markdown Project | |
# License: [BSD](https://opensource.org/licenses/bsd-license.php) | |
""" | |
Added parsing of tables to Python-Markdown. | |
See the [documentation](https://Python-Markdown.github.io/extensions/tables) | |
for details. | |
""" | |
from __future__ import annotations | |
from . import Extension | |
from ..blockprocessors import BlockProcessor | |
import xml.etree.ElementTree as etree | |
import re | |
from typing import TYPE_CHECKING, Any, Sequence | |
if TYPE_CHECKING: # pragma: no cover | |
from .. import blockparser | |
PIPE_NONE = 0 | |
PIPE_LEFT = 1 | |
PIPE_RIGHT = 2 | |
class TableProcessor(BlockProcessor): | |
""" Process Tables. """ | |
RE_CODE_PIPES = re.compile(r'(?:(\\\\)|(\\`+)|(`+)|(\\\|)|(\|))') | |
RE_END_BORDER = re.compile(r'(?<!\\)(?:\\\\)*\|$') | |
def __init__(self, parser: blockparser.BlockParser, config: dict[str, Any]): | |
self.border: bool | int = False | |
self.separator: Sequence[str] = '' | |
self.config = config | |
super().__init__(parser) | |
def test(self, parent: etree.Element, block: str) -> bool: | |
""" | |
Ensure first two rows (column header and separator row) are valid table rows. | |
Keep border check and separator row do avoid repeating the work. | |
""" | |
is_table = False | |
rows = [row.strip(' ') for row in block.split('\n')] | |
if len(rows) > 1: | |
header0 = rows[0] | |
self.border = PIPE_NONE | |
if header0.startswith('|'): | |
self.border |= PIPE_LEFT | |
if self.RE_END_BORDER.search(header0) is not None: | |
self.border |= PIPE_RIGHT | |
row = self._split_row(header0) | |
row0_len = len(row) | |
is_table = row0_len > 1 | |
# Each row in a single column table needs at least one pipe. | |
if not is_table and row0_len == 1 and self.border: | |
for index in range(1, len(rows)): | |
is_table = rows[index].startswith('|') | |
if not is_table: | |
is_table = self.RE_END_BORDER.search(rows[index]) is not None | |
if not is_table: | |
break | |
if is_table: | |
row = self._split_row(rows[1]) | |
is_table = (len(row) == row0_len) and set(''.join(row)) <= set('|:- ') | |
if is_table: | |
self.separator = row | |
return is_table | |
def run(self, parent: etree.Element, blocks: list[str]) -> None: | |
""" Parse a table block and build table. """ | |
block = blocks.pop(0).split('\n') | |
header = block[0].strip(' ') | |
rows = [] if len(block) < 3 else block[2:] | |
# Get alignment of columns | |
align: list[str | None] = [] | |
for c in self.separator: | |
c = c.strip(' ') | |
if c.startswith(':') and c.endswith(':'): | |
align.append('center') | |
elif c.startswith(':'): | |
align.append('left') | |
elif c.endswith(':'): | |
align.append('right') | |
else: | |
align.append(None) | |
# Build table | |
table = etree.SubElement(parent, 'table') | |
thead = etree.SubElement(table, 'thead') | |
self._build_row(header, thead, align) | |
tbody = etree.SubElement(table, 'tbody') | |
if len(rows) == 0: | |
# Handle empty table | |
self._build_empty_row(tbody, align) | |
else: | |
for row in rows: | |
self._build_row(row.strip(' '), tbody, align) | |
def _build_empty_row(self, parent: etree.Element, align: Sequence[str | None]) -> None: | |
"""Build an empty row.""" | |
tr = etree.SubElement(parent, 'tr') | |
count = len(align) | |
while count: | |
etree.SubElement(tr, 'td') | |
count -= 1 | |
def _build_row(self, row: str, parent: etree.Element, align: Sequence[str | None]) -> None: | |
""" Given a row of text, build table cells. """ | |
tr = etree.SubElement(parent, 'tr') | |
tag = 'td' | |
if parent.tag == 'thead': | |
tag = 'th' | |
cells = self._split_row(row) | |
# We use align here rather than cells to ensure every row | |
# contains the same number of columns. | |
for i, a in enumerate(align): | |
c = etree.SubElement(tr, tag) | |
try: | |
c.text = cells[i].strip(' ') | |
except IndexError: # pragma: no cover | |
c.text = "" | |
if a: | |
if self.config['use_align_attribute']: | |
c.set('align', a) | |
else: | |
c.set('style', f'text-align: {a};') | |
def _split_row(self, row: str) -> list[str]: | |
""" split a row of text into list of cells. """ | |
if self.border: | |
if row.startswith('|'): | |
row = row[1:] | |
row = self.RE_END_BORDER.sub('', row) | |
return self._split(row) | |
def _split(self, row: str) -> list[str]: | |
""" split a row of text with some code into a list of cells. """ | |
elements = [] | |
pipes = [] | |
tics = [] | |
tic_points = [] | |
tic_region = [] | |
good_pipes = [] | |
# Parse row | |
# Throw out \\, and \| | |
for m in self.RE_CODE_PIPES.finditer(row): | |
# Store ` data (len, start_pos, end_pos) | |
if m.group(2): | |
# \`+ | |
# Store length of each tic group: subtract \ | |
tics.append(len(m.group(2)) - 1) | |
# Store start of group, end of group, and escape length | |
tic_points.append((m.start(2), m.end(2) - 1, 1)) | |
elif m.group(3): | |
# `+ | |
# Store length of each tic group | |
tics.append(len(m.group(3))) | |
# Store start of group, end of group, and escape length | |
tic_points.append((m.start(3), m.end(3) - 1, 0)) | |
# Store pipe location | |
elif m.group(5): | |
pipes.append(m.start(5)) | |
# Pair up tics according to size if possible | |
# Subtract the escape length *only* from the opening. | |
# Walk through tic list and see if tic has a close. | |
# Store the tic region (start of region, end of region). | |
pos = 0 | |
tic_len = len(tics) | |
while pos < tic_len: | |
try: | |
tic_size = tics[pos] - tic_points[pos][2] | |
if tic_size == 0: | |
raise ValueError | |
index = tics[pos + 1:].index(tic_size) + 1 | |
tic_region.append((tic_points[pos][0], tic_points[pos + index][1])) | |
pos += index + 1 | |
except ValueError: | |
pos += 1 | |
# Resolve pipes. Check if they are within a tic pair region. | |
# Walk through pipes comparing them to each region. | |
# - If pipe position is less that a region, it isn't in a region | |
# - If it is within a region, we don't want it, so throw it out | |
# - If we didn't throw it out, it must be a table pipe | |
for pipe in pipes: | |
throw_out = False | |
for region in tic_region: | |
if pipe < region[0]: | |
# Pipe is not in a region | |
break | |
elif region[0] <= pipe <= region[1]: | |
# Pipe is within a code region. Throw it out. | |
throw_out = True | |
break | |
if not throw_out: | |
good_pipes.append(pipe) | |
# Split row according to table delimiters. | |
pos = 0 | |
for pipe in good_pipes: | |
elements.append(row[pos:pipe]) | |
pos = pipe + 1 | |
elements.append(row[pos:]) | |
return elements | |
class TableExtension(Extension): | |
""" Add tables to Markdown. """ | |
def __init__(self, **kwargs): | |
self.config = { | |
'use_align_attribute': [False, 'True to use align attribute instead of style.'], | |
} | |
""" Default configuration options. """ | |
super().__init__(**kwargs) | |
def extendMarkdown(self, md): | |
""" Add an instance of `TableProcessor` to `BlockParser`. """ | |
if '|' not in md.ESCAPED_CHARS: | |
md.ESCAPED_CHARS.append('|') | |
processor = TableProcessor(md.parser, self.getConfigs()) | |
md.parser.blockprocessors.register(processor, 'table', 75) | |
def makeExtension(**kwargs): # pragma: no cover | |
return TableExtension(**kwargs) | |