Files
python-markdownify/markdownify/__init__.py
Joseph Myers c13bdd5c14 Fix logic for indentation inside list items
This fixes problems with the markdownify logic for indentation inside
list items.

This PR uses a branch building on that for #120, #150 and #151, so
those three PRs should be merged first before merging this one.

There is limited logic in markdownify for handling indentation in the
case of nested lists.  There are two major problems with this logic:

* As it's in `convert_list`, causing a list to be indented when inside
  another list, it does not add indentation for any other elements
  such as paragraphs that may be found inside list items (or `<pre>`,
  `<blockquote>`, etc.), so such elements are wrongly not indented and
  terminate the list in the output.

* It uses fixed indentation of one tab.  Following CommonMark, a tab
  in Markdown is considered equivalent to four spaces, which is not
  sufficient indentation in ordered list items with a number of three
  or more digits.

Fix both of these issues by making `convert_li` handle indentation for
the contents of `<li>`, based on the length of the list item marker,
rather than doing it in `convert_list` at all.
2024-10-03 21:04:40 +00:00

479 lines
17 KiB
Python

from bs4 import BeautifulSoup, NavigableString, Comment, Doctype
from textwrap import fill
import re
import six
convert_heading_re = re.compile(r'convert_h(\d+)')
line_beginning_re = re.compile(r'^', re.MULTILINE)
whitespace_re = re.compile(r'[\t ]+')
all_whitespace_re = re.compile(r'[\t \r\n]+')
newline_whitespace_re = re.compile(r'[\t \r\n]*[\r\n][\t \r\n]*')
html_heading_re = re.compile(r'h[1-6]')
# Heading styles
ATX = 'atx'
ATX_CLOSED = 'atx_closed'
UNDERLINED = 'underlined'
SETEXT = UNDERLINED
# Newline style
SPACES = 'spaces'
BACKSLASH = 'backslash'
# Strong and emphasis style
ASTERISK = '*'
UNDERSCORE = '_'
def chomp(text):
"""
If the text in an inline tag like b, a, or em contains a leading or trailing
space, strip the string and return a space as suffix of prefix, if needed.
This function is used to prevent conversions like
<b> foo</b> => ** foo**
"""
prefix = ' ' if text and text[0] == ' ' else ''
suffix = ' ' if text and text[-1] == ' ' else ''
text = text.strip()
return (prefix, suffix, text)
def abstract_inline_conversion(markup_fn):
"""
This abstracts all simple inline tags like b, em, del, ...
Returns a function that wraps the chomped text in a pair of the string
that is returned by markup_fn, with '/' inserted in the string used after
the text if it looks like an HTML tag. markup_fn is necessary to allow for
references to self.strong_em_symbol etc.
"""
def implementation(self, el, text, convert_as_inline):
markup_prefix = markup_fn(self)
if markup_prefix.startswith('<') and markup_prefix.endswith('>'):
markup_suffix = '</' + markup_prefix[1:]
else:
markup_suffix = markup_prefix
if el.find_parent(['pre', 'code', 'kbd', 'samp']):
return text
prefix, suffix, text = chomp(text)
if not text:
return ''
return '%s%s%s%s%s' % (prefix, markup_prefix, text, markup_suffix, suffix)
return implementation
def _todict(obj):
return dict((k, getattr(obj, k)) for k in dir(obj) if not k.startswith('_'))
def remove_whitespace_inside(el):
"""Return to remove whitespace immediately inside a block-level element."""
if not el or not el.name:
return False
if html_heading_re.match(el.name) is not None:
return True
return el.name in ('p', 'blockquote',
'ol', 'ul', 'li',
'table', 'thead', 'tbody', 'tfoot',
'tr', 'td', 'th')
def remove_whitespace_outside(el):
"""Return to remove whitespace immediately outside a block-level element."""
return remove_whitespace_inside(el) or (el and el.name == 'pre')
class MarkdownConverter(object):
class DefaultOptions:
autolinks = True
bullets = '*+-' # An iterable of bullet types.
code_language = ''
code_language_callback = None
convert = None
default_title = False
escape_asterisks = True
escape_underscores = True
escape_misc = True
heading_style = UNDERLINED
keep_inline_images_in = []
newline_style = SPACES
strip = None
strong_em_symbol = ASTERISK
sub_symbol = ''
sup_symbol = ''
wrap = False
wrap_width = 80
class Options(DefaultOptions):
pass
def __init__(self, **options):
# Create an options dictionary. Use DefaultOptions as a base so that
# it doesn't have to be extended.
self.options = _todict(self.DefaultOptions)
self.options.update(_todict(self.Options))
self.options.update(options)
if self.options['strip'] is not None and self.options['convert'] is not None:
raise ValueError('You may specify either tags to strip or tags to'
' convert, but not both.')
def convert(self, html):
soup = BeautifulSoup(html, 'html.parser')
return self.convert_soup(soup)
def convert_soup(self, soup):
return self.process_tag(soup, convert_as_inline=False, children_only=True)
def process_tag(self, node, convert_as_inline, children_only=False):
text = ''
# markdown headings or cells can't include
# block elements (elements w/newlines)
isHeading = html_heading_re.match(node.name) is not None
isCell = node.name in ['td', 'th']
convert_children_as_inline = convert_as_inline
if not children_only and (isHeading or isCell):
convert_children_as_inline = True
# Remove whitespace-only textnodes just before, after or
# inside block-level elements.
remove_inside = remove_whitespace_inside(node)
for el in node.children:
# Only extract (remove) whitespace-only text node if any of the
# conditions is true:
# - el is the first element in its parent (block-level)
# - el is the last element in its parent (block-level)
# - el is adjacent to a block-level node
can_extract = (remove_inside and (not el.previous_sibling
or not el.next_sibling)
or remove_whitespace_outside(el.previous_sibling)
or remove_whitespace_outside(el.next_sibling))
if (isinstance(el, NavigableString)
and six.text_type(el).strip() == ''
and can_extract):
el.extract()
# Convert the children first
for el in node.children:
if isinstance(el, Comment) or isinstance(el, Doctype):
continue
elif isinstance(el, NavigableString):
text += self.process_text(el)
else:
text_strip = text.rstrip('\n')
newlines_left = len(text) - len(text_strip)
next_text = self.process_tag(el, convert_children_as_inline)
next_text_strip = next_text.lstrip('\n')
newlines_right = len(next_text) - len(next_text_strip)
newlines = '\n' * max(newlines_left, newlines_right)
text = text_strip + newlines + next_text_strip
if not children_only:
convert_fn = getattr(self, 'convert_%s' % node.name, None)
if convert_fn and self.should_convert_tag(node.name):
text = convert_fn(node, text, convert_as_inline)
return text
def process_text(self, el):
text = six.text_type(el) or ''
# normalize whitespace if we're not inside a preformatted element
if not el.find_parent('pre'):
if self.options['wrap']:
text = all_whitespace_re.sub(' ', text)
else:
text = newline_whitespace_re.sub('\n', text)
text = whitespace_re.sub(' ', text)
# escape special characters if we're not inside a preformatted or code element
if not el.find_parent(['pre', 'code', 'kbd', 'samp']):
text = self.escape(text)
# remove leading whitespace at the start or just after a
# block-level element; remove traliing whitespace at the end
# or just before a block-level element.
if (remove_whitespace_outside(el.previous_sibling)
or (remove_whitespace_inside(el.parent)
and not el.previous_sibling)):
text = text.lstrip()
if (remove_whitespace_outside(el.next_sibling)
or (remove_whitespace_inside(el.parent)
and not el.next_sibling)):
text = text.rstrip()
return text
def __getattr__(self, attr):
# Handle headings
m = convert_heading_re.match(attr)
if m:
n = int(m.group(1))
def convert_tag(el, text, convert_as_inline):
return self.convert_hn(n, el, text, convert_as_inline)
convert_tag.__name__ = 'convert_h%s' % n
setattr(self, convert_tag.__name__, convert_tag)
return convert_tag
raise AttributeError(attr)
def should_convert_tag(self, tag):
tag = tag.lower()
strip = self.options['strip']
convert = self.options['convert']
if strip is not None:
return tag not in strip
elif convert is not None:
return tag in convert
else:
return True
def escape(self, text):
if not text:
return ''
if self.options['escape_misc']:
text = re.sub(r'([\\&<`[>~#=+|-])', r'\\\1', text)
text = re.sub(r'([0-9])([.)])', r'\1\\\2', text)
if self.options['escape_asterisks']:
text = text.replace('*', r'\*')
if self.options['escape_underscores']:
text = text.replace('_', r'\_')
return text
def indent(self, text, columns):
return line_beginning_re.sub(' ' * columns, text) if text else ''
def underline(self, text, pad_char):
text = (text or '').rstrip()
return '\n\n%s\n%s\n\n' % (text, pad_char * len(text)) if text else ''
def convert_a(self, el, text, convert_as_inline):
prefix, suffix, text = chomp(text)
if not text:
return ''
href = el.get('href')
title = el.get('title')
# For the replacement see #29: text nodes underscores are escaped
if (self.options['autolinks']
and text.replace(r'\_', '_') == href
and not title
and not self.options['default_title']):
# Shortcut syntax
return '<%s>' % href
if self.options['default_title'] and not title:
title = href
title_part = ' "%s"' % title.replace('"', r'\"') if title else ''
return '%s[%s](%s%s)%s' % (prefix, text, href, title_part, suffix) if href else text
convert_b = abstract_inline_conversion(lambda self: 2 * self.options['strong_em_symbol'])
def convert_blockquote(self, el, text, convert_as_inline):
if convert_as_inline:
return ' ' + text.strip() + ' '
return '\n' + (line_beginning_re.sub('> ', text.strip()) + '\n\n') if text else ''
def convert_br(self, el, text, convert_as_inline):
if convert_as_inline:
return ""
if self.options['newline_style'].lower() == BACKSLASH:
return '\\\n'
else:
return ' \n'
def convert_code(self, el, text, convert_as_inline):
if el.parent.name == 'pre':
return text
converter = abstract_inline_conversion(lambda self: '`')
return converter(self, el, text, convert_as_inline)
convert_del = abstract_inline_conversion(lambda self: '~~')
convert_em = abstract_inline_conversion(lambda self: self.options['strong_em_symbol'])
convert_kbd = convert_code
def convert_hn(self, n, el, text, convert_as_inline):
if convert_as_inline:
return text
style = self.options['heading_style'].lower()
text = text.strip()
if style == UNDERLINED and n <= 2:
line = '=' if n == 1 else '-'
return self.underline(text, line)
text = all_whitespace_re.sub(' ', text)
hashes = '#' * n
if style == ATX_CLOSED:
return '\n%s %s %s\n\n' % (hashes, text, hashes)
return '\n%s %s\n\n' % (hashes, text)
def convert_hr(self, el, text, convert_as_inline):
return '\n\n---\n\n'
convert_i = convert_em
def convert_img(self, el, text, convert_as_inline):
alt = el.attrs.get('alt', None) or ''
src = el.attrs.get('src', None) or ''
title = el.attrs.get('title', None) or ''
title_part = ' "%s"' % title.replace('"', r'\"') if title else ''
if (convert_as_inline
and el.parent.name not in self.options['keep_inline_images_in']):
return alt
return '![%s](%s%s)' % (alt, src, title_part)
def convert_list(self, el, text, convert_as_inline):
# Converting a list to inline is undefined.
# Ignoring convert_to_inline for list.
nested = False
before_paragraph = False
if el.next_sibling and el.next_sibling.name not in ['ul', 'ol']:
before_paragraph = True
while el:
if el.name == 'li':
nested = True
break
el = el.parent
if nested:
# remove trailing newline if nested
return '\n' + text.rstrip()
return '\n\n' + text + ('\n' if before_paragraph else '')
convert_ul = convert_list
convert_ol = convert_list
def convert_li(self, el, text, convert_as_inline):
parent = el.parent
if parent is not None and parent.name == 'ol':
if parent.get("start") and str(parent.get("start")).isnumeric():
start = int(parent.get("start"))
else:
start = 1
bullet = '%s.' % (start + parent.index(el))
else:
depth = -1
while el:
if el.name == 'ul':
depth += 1
el = el.parent
bullets = self.options['bullets']
bullet = bullets[depth % len(bullets)]
bullet = bullet + ' '
text = (text or '').strip()
text = self.indent(text, len(bullet))
if text:
text = bullet + text[len(bullet):]
return '%s\n' % text
def convert_p(self, el, text, convert_as_inline):
if convert_as_inline:
return ' ' + text.strip() + ' '
if self.options['wrap']:
# Preserve newlines (and preceding whitespace) resulting
# from <br> tags. Newlines in the input have already been
# replaced by spaces.
lines = text.split('\n')
new_lines = []
for line in lines:
line = line.lstrip()
line_no_trailing = line.rstrip()
trailing = line[len(line_no_trailing):]
line = fill(line,
width=self.options['wrap_width'],
break_long_words=False,
break_on_hyphens=False)
new_lines.append(line + trailing)
text = '\n'.join(new_lines)
return '\n\n%s\n\n' % text if text else ''
def convert_pre(self, el, text, convert_as_inline):
if not text:
return ''
code_language = self.options['code_language']
if self.options['code_language_callback']:
code_language = self.options['code_language_callback'](el) or code_language
return '\n```%s\n%s\n```\n' % (code_language, text)
def convert_script(self, el, text, convert_as_inline):
return ''
def convert_style(self, el, text, convert_as_inline):
return ''
convert_s = convert_del
convert_strong = convert_b
convert_samp = convert_code
convert_sub = abstract_inline_conversion(lambda self: self.options['sub_symbol'])
convert_sup = abstract_inline_conversion(lambda self: self.options['sup_symbol'])
def convert_table(self, el, text, convert_as_inline):
return '\n\n' + text + '\n'
def convert_caption(self, el, text, convert_as_inline):
return text + '\n'
def convert_figcaption(self, el, text, convert_as_inline):
return '\n\n' + text + '\n\n'
def convert_td(self, el, text, convert_as_inline):
colspan = 1
if 'colspan' in el.attrs and el['colspan'].isdigit():
colspan = int(el['colspan'])
return ' ' + text.strip().replace("\n", " ") + ' |' * colspan
def convert_th(self, el, text, convert_as_inline):
colspan = 1
if 'colspan' in el.attrs and el['colspan'].isdigit():
colspan = int(el['colspan'])
return ' ' + text.strip().replace("\n", " ") + ' |' * colspan
def convert_tr(self, el, text, convert_as_inline):
cells = el.find_all(['td', 'th'])
is_headrow = (
all([cell.name == 'th' for cell in cells])
or (not el.previous_sibling and not el.parent.name == 'tbody')
or (not el.previous_sibling and el.parent.name == 'tbody' and len(el.parent.parent.find_all(['thead'])) < 1)
)
overline = ''
underline = ''
if is_headrow and not el.previous_sibling:
# first row and is headline: print headline underline
full_colspan = 0
for cell in cells:
if 'colspan' in cell.attrs and cell['colspan'].isdigit():
full_colspan += int(cell["colspan"])
else:
full_colspan += 1
underline += '| ' + ' | '.join(['---'] * full_colspan) + ' |' + '\n'
elif (not el.previous_sibling
and (el.parent.name == 'table'
or (el.parent.name == 'tbody'
and not el.parent.previous_sibling))):
# first row, not headline, and:
# - the parent is table or
# - the parent is tbody at the beginning of a table.
# print empty headline above this row
overline += '| ' + ' | '.join([''] * len(cells)) + ' |' + '\n'
overline += '| ' + ' | '.join(['---'] * len(cells)) + ' |' + '\n'
return overline + '|' + text + '\n' + underline
def markdownify(html, **options):
return MarkdownConverter(**options).convert(html)