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personal-data/personal_data/html_util.py
2024-10-25 22:24:33 +02:00

115 lines
2.9 KiB
Python

import re
from collections.abc import Iterator
import bs4
HTML_TAGS_MOSTLY_CONTENTLESS: set[str] = {
'style',
'svg',
'link',
'br',
'math',
'canvas',
}
HTML_TAGS_WITH_LITTLE_CONTENT: set[str] = {
'head',
'script',
'meta',
} | HTML_TAGS_MOSTLY_CONTENTLESS
def normalize_text(text: str) -> bytes:
text = text.replace('\t', ' ')
text = text.replace('\r', '')
text = re.sub(r'\s*\n\s*\n\s*', '\n\n', text)
text = re.sub(r' +', ' ', text)
text = re.sub(r'^\s+', '', text)
text = re.sub(r'\s+$', '', text)
return text.encode('utf-8')
def normalize_soup_bs4(soup: bs4.BeautifulSoup) -> bs4.BeautifulSoup:
for comment in soup(text=lambda text: isinstance(text, bs4.Comment)):
comment.extract()
del comment
for element_name in HTML_TAGS_WITH_LITTLE_CONTENT:
for script_elements in soup(element_name):
script_elements.decompose()
del element_name
soup.smooth()
return soup
def normalize_soup_lxml(soup):
for element_name in HTML_TAGS_WITH_LITTLE_CONTENT:
for script_elements in soup.cssselect(element_name):
script_elements.drop_tree()
del script_elements
del element_name
return soup
def normalize_soup(soup) -> bytes:
if isinstance(soup, bs4.BeautifulSoup):
text = normalize_soup_bs4(soup).get_text()
else:
text = normalize_soup_lxml(soup).text_content()
return normalize_text(text)
def data_attributes_of_element(e) -> Iterator[str]:
for attr_key in list(e.attrs.keys()):
if attr_key.startswith('data-'):
yield attr_key
def has_data_attribute(e) -> bool:
for _ in data_attributes_of_element(e):
return True
return False
def normalize_soup_slightly(
soup: bs4.BeautifulSoup,
classes=True,
scripts=True,
comments=True,
data_attributes=True,
) -> bs4.BeautifulSoup:
"""Perform soup normalization."""
# Little if any content
for tag in HTML_TAGS_MOSTLY_CONTENTLESS:
for e in soup.select(tag):
e.decompose()
if classes:
for e in soup.find_all(class_=True):
del e['class']
for e in soup.find_all('script', src=True):
e.decompose()
for e in soup.find_all(style=True):
del e['style']
for e in soup.select('a'):
del e['height'], e['target'], e['rel'], e['onclick']
for e in soup.select('a[href=""]'):
del e['href']
if scripts:
for e in soup.find_all('script'):
e.decompose()
if comments:
for c in soup.find_all(string=lambda text: isinstance(text, bs4.Comment)):
c.extract()
if data_attributes:
for e in soup.find_all(has_data_attribute):
for attr_key in data_attributes_of_element(e):
del e[attr_key], attr_key
del e
soup.smooth()
return soup