[utils] Improve parsing for nested HTML elements (#2129)

and add functions to return the HTML of elements

Authored by: zmousm
This commit is contained in:
Zenon Mousmoulas 2022-01-05 20:37:49 +02:00 committed by GitHub
parent e8736539f3
commit 6f32a0b5b7
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2 changed files with 216 additions and 28 deletions

View file

@ -44,6 +44,12 @@ from yt_dlp.utils import (
get_element_by_attribute,
get_elements_by_class,
get_elements_by_attribute,
get_element_html_by_class,
get_element_html_by_attribute,
get_elements_html_by_class,
get_elements_html_by_attribute,
get_elements_text_and_html_by_attribute,
get_element_text_and_html_by_tag,
InAdvancePagedList,
int_or_none,
intlist_to_bytes,
@ -118,6 +124,7 @@ from yt_dlp.compat import (
compat_chr,
compat_etree_fromstring,
compat_getenv,
compat_HTMLParseError,
compat_os_name,
compat_setenv,
)
@ -1575,46 +1582,116 @@ Line 1
self.assertEqual(urshift(3, 1), 1)
self.assertEqual(urshift(-3, 1), 2147483646)
def test_get_element_by_class(self):
html = '''
GET_ELEMENT_BY_CLASS_TEST_STRING = '''
<span class="foo bar">nice</span>
'''
def test_get_element_by_class(self):
html = self.GET_ELEMENT_BY_CLASS_TEST_STRING
self.assertEqual(get_element_by_class('foo', html), 'nice')
self.assertEqual(get_element_by_class('no-such-class', html), None)
def test_get_element_by_attribute(self):
html = '''
<span class="foo bar">nice</span>
def test_get_element_html_by_class(self):
html = self.GET_ELEMENT_BY_CLASS_TEST_STRING
self.assertEqual(get_element_html_by_class('foo', html), html.strip())
self.assertEqual(get_element_by_class('no-such-class', html), None)
GET_ELEMENT_BY_ATTRIBUTE_TEST_STRING = '''
<div itemprop="author" itemscope>foo</div>
'''
def test_get_element_by_attribute(self):
html = self.GET_ELEMENT_BY_CLASS_TEST_STRING
self.assertEqual(get_element_by_attribute('class', 'foo bar', html), 'nice')
self.assertEqual(get_element_by_attribute('class', 'foo', html), None)
self.assertEqual(get_element_by_attribute('class', 'no-such-foo', html), None)
html = '''
<div itemprop="author" itemscope>foo</div>
'''
html = self.GET_ELEMENT_BY_ATTRIBUTE_TEST_STRING
self.assertEqual(get_element_by_attribute('itemprop', 'author', html), 'foo')
def test_get_elements_by_class(self):
html = '''
def test_get_element_html_by_attribute(self):
html = self.GET_ELEMENT_BY_CLASS_TEST_STRING
self.assertEqual(get_element_html_by_attribute('class', 'foo bar', html), html.strip())
self.assertEqual(get_element_html_by_attribute('class', 'foo', html), None)
self.assertEqual(get_element_html_by_attribute('class', 'no-such-foo', html), None)
html = self.GET_ELEMENT_BY_ATTRIBUTE_TEST_STRING
self.assertEqual(get_element_html_by_attribute('itemprop', 'author', html), html.strip())
GET_ELEMENTS_BY_CLASS_TEST_STRING = '''
<span class="foo bar">nice</span><span class="foo bar">also nice</span>
'''
GET_ELEMENTS_BY_CLASS_RES = ['<span class="foo bar">nice</span>', '<span class="foo bar">also nice</span>']
def test_get_elements_by_class(self):
html = self.GET_ELEMENTS_BY_CLASS_TEST_STRING
self.assertEqual(get_elements_by_class('foo', html), ['nice', 'also nice'])
self.assertEqual(get_elements_by_class('no-such-class', html), [])
def test_get_elements_html_by_class(self):
html = self.GET_ELEMENTS_BY_CLASS_TEST_STRING
self.assertEqual(get_elements_html_by_class('foo', html), self.GET_ELEMENTS_BY_CLASS_RES)
self.assertEqual(get_elements_html_by_class('no-such-class', html), [])
def test_get_elements_by_attribute(self):
html = '''
<span class="foo bar">nice</span><span class="foo bar">also nice</span>
'''
html = self.GET_ELEMENTS_BY_CLASS_TEST_STRING
self.assertEqual(get_elements_by_attribute('class', 'foo bar', html), ['nice', 'also nice'])
self.assertEqual(get_elements_by_attribute('class', 'foo', html), [])
self.assertEqual(get_elements_by_attribute('class', 'no-such-foo', html), [])
def test_get_elements_html_by_attribute(self):
html = self.GET_ELEMENTS_BY_CLASS_TEST_STRING
self.assertEqual(get_elements_html_by_attribute('class', 'foo bar', html), self.GET_ELEMENTS_BY_CLASS_RES)
self.assertEqual(get_elements_html_by_attribute('class', 'foo', html), [])
self.assertEqual(get_elements_html_by_attribute('class', 'no-such-foo', html), [])
def test_get_elements_text_and_html_by_attribute(self):
html = self.GET_ELEMENTS_BY_CLASS_TEST_STRING
self.assertEqual(
get_elements_text_and_html_by_attribute('class', 'foo bar', html),
list(zip(['nice', 'also nice'], self.GET_ELEMENTS_BY_CLASS_RES)))
self.assertEqual(get_elements_text_and_html_by_attribute('class', 'foo', html), [])
self.assertEqual(get_elements_text_and_html_by_attribute('class', 'no-such-foo', html), [])
GET_ELEMENT_BY_TAG_TEST_STRING = '''
random text lorem ipsum</p>
<div>
this should be returned
<span>this should also be returned</span>
<div>
this should also be returned
</div>
closing tag above should not trick, so this should also be returned
</div>
but this text should not be returned
'''
GET_ELEMENT_BY_TAG_RES_OUTERDIV_HTML = GET_ELEMENT_BY_TAG_TEST_STRING.strip()[32:276]
GET_ELEMENT_BY_TAG_RES_OUTERDIV_TEXT = GET_ELEMENT_BY_TAG_RES_OUTERDIV_HTML[5:-6]
GET_ELEMENT_BY_TAG_RES_INNERSPAN_HTML = GET_ELEMENT_BY_TAG_TEST_STRING.strip()[78:119]
GET_ELEMENT_BY_TAG_RES_INNERSPAN_TEXT = GET_ELEMENT_BY_TAG_RES_INNERSPAN_HTML[6:-7]
def test_get_element_text_and_html_by_tag(self):
html = self.GET_ELEMENT_BY_TAG_TEST_STRING
self.assertEqual(
get_element_text_and_html_by_tag('div', html),
(self.GET_ELEMENT_BY_TAG_RES_OUTERDIV_TEXT, self.GET_ELEMENT_BY_TAG_RES_OUTERDIV_HTML))
self.assertEqual(
get_element_text_and_html_by_tag('span', html),
(self.GET_ELEMENT_BY_TAG_RES_INNERSPAN_TEXT, self.GET_ELEMENT_BY_TAG_RES_INNERSPAN_HTML))
self.assertRaises(compat_HTMLParseError, get_element_text_and_html_by_tag, 'article', html)
def test_iri_to_uri(self):
self.assertEqual(
iri_to_uri('https://www.google.com/search?q=foo&ie=utf-8&oe=utf-8&client=firefox-b'),

View file

@ -416,17 +416,33 @@ def get_element_by_id(id, html):
return get_element_by_attribute('id', id, html)
def get_element_html_by_id(id, html):
"""Return the html of the tag with the specified ID in the passed HTML document"""
return get_element_html_by_attribute('id', id, html)
def get_element_by_class(class_name, html):
"""Return the content of the first tag with the specified class in the passed HTML document"""
retval = get_elements_by_class(class_name, html)
return retval[0] if retval else None
def get_element_html_by_class(class_name, html):
"""Return the html of the first tag with the specified class in the passed HTML document"""
retval = get_elements_html_by_class(class_name, html)
return retval[0] if retval else None
def get_element_by_attribute(attribute, value, html, escape_value=True):
retval = get_elements_by_attribute(attribute, value, html, escape_value)
return retval[0] if retval else None
def get_element_html_by_attribute(attribute, value, html, escape_value=True):
retval = get_elements_html_by_attribute(attribute, value, html, escape_value)
return retval[0] if retval else None
def get_elements_by_class(class_name, html):
"""Return the content of all tags with the specified class in the passed HTML document as a list"""
return get_elements_by_attribute(
@ -434,31 +450,126 @@ def get_elements_by_class(class_name, html):
html, escape_value=False)
def get_elements_by_attribute(attribute, value, html, escape_value=True):
def get_elements_html_by_class(class_name, html):
"""Return the html of all tags with the specified class in the passed HTML document as a list"""
return get_elements_html_by_attribute(
'class', r'[^\'"]*\b%s\b[^\'"]*' % re.escape(class_name),
html, escape_value=False)
def get_elements_by_attribute(*args, **kwargs):
"""Return the content of the tag with the specified attribute in the passed HTML document"""
return [content for content, _ in get_elements_text_and_html_by_attribute(*args, **kwargs)]
def get_elements_html_by_attribute(*args, **kwargs):
"""Return the html of the tag with the specified attribute in the passed HTML document"""
return [whole for _, whole in get_elements_text_and_html_by_attribute(*args, **kwargs)]
def get_elements_text_and_html_by_attribute(attribute, value, html, escape_value=True):
"""
Return the text (content) and the html (whole) of the tag with the specified
attribute in the passed HTML document
"""
value = re.escape(value) if escape_value else value
retlist = []
for m in re.finditer(r'''(?xs)
<([a-zA-Z0-9:._-]+)
(?:\s+[a-zA-Z0-9:._-]+(?:=[a-zA-Z0-9:._-]*|="[^"]*"|='[^']*'|))*?
\s+%s=['"]?%s['"]?
(?:\s+[a-zA-Z0-9:._-]+(?:=[a-zA-Z0-9:._-]*|="[^"]*"|='[^']*'|))*?
<(?P<tag>[a-zA-Z0-9:._-]+)
(?:\s+[a-zA-Z0-9_:.-]+(?:=\S*?|\s*=\s*(?:"[^"]*"|'[^']*')|))*?
\s+%(attribute)s(?:=%(value)s|\s*=\s*(?P<_q>['"]?)%(value)s(?P=_q))
(?:\s+[a-zA-Z0-9_:.-]+(?:=\S*?|\s*=\s*(?:"[^"]*"|'[^']*')|))*?
\s*>
(?P<content>.*?)
</\1>
''' % (re.escape(attribute), value), html):
res = m.group('content')
''' % {'attribute': re.escape(attribute), 'value': value}, html):
content, whole = get_element_text_and_html_by_tag(m.group('tag'), html[m.start():])
if res.startswith('"') or res.startswith("'"):
res = res[1:-1]
retlist.append(unescapeHTML(res))
retlist.append((
unescapeHTML(re.sub(r'(?s)^(?P<q>["\'])(?P<content>.*)(?P=q)$', r'\g<content>', content)),
whole,
))
return retlist
class HTMLBreakOnClosingTagParser(compat_HTMLParser):
"""
HTML parser which raises HTMLBreakOnClosingTagException upon reaching the
closing tag for the first opening tag it has encountered, and can be used
as a context manager
"""
class HTMLBreakOnClosingTagException(Exception):
pass
def __init__(self):
self.tagstack = collections.deque()
compat_HTMLParser.__init__(self)
def __enter__(self):
return self
def __exit__(self, *_):
self.close()
def close(self):
# handle_endtag does not return upon raising HTMLBreakOnClosingTagException,
# so data remains buffered; we no longer have any interest in it, thus
# override this method to discard it
pass
def handle_starttag(self, tag, _):
self.tagstack.append(tag)
def handle_endtag(self, tag):
if not self.tagstack:
raise compat_HTMLParseError('no tags in the stack')
while self.tagstack:
inner_tag = self.tagstack.pop()
if inner_tag == tag:
break
else:
raise compat_HTMLParseError(f'matching opening tag for closing {tag} tag not found')
if not self.tagstack:
raise self.HTMLBreakOnClosingTagException()
def get_element_text_and_html_by_tag(tag, html):
"""
For the first element with the specified tag in the passed HTML document
return its' content (text) and the whole element (html)
"""
def find_or_raise(haystack, needle, exc):
try:
return haystack.index(needle)
except ValueError:
raise exc
closing_tag = f'</{tag}>'
whole_start = find_or_raise(
html, f'<{tag}', compat_HTMLParseError(f'opening {tag} tag not found'))
content_start = find_or_raise(
html[whole_start:], '>', compat_HTMLParseError(f'malformed opening {tag} tag'))
content_start += whole_start + 1
with HTMLBreakOnClosingTagParser() as parser:
parser.feed(html[whole_start:content_start])
if not parser.tagstack or parser.tagstack[0] != tag:
raise compat_HTMLParseError(f'parser did not match opening {tag} tag')
offset = content_start
while offset < len(html):
next_closing_tag_start = find_or_raise(
html[offset:], closing_tag,
compat_HTMLParseError(f'closing {tag} tag not found'))
next_closing_tag_end = next_closing_tag_start + len(closing_tag)
try:
parser.feed(html[offset:offset + next_closing_tag_end])
offset += next_closing_tag_end
except HTMLBreakOnClosingTagParser.HTMLBreakOnClosingTagException:
return html[content_start:offset + next_closing_tag_start], \
html[whole_start:offset + next_closing_tag_end]
raise compat_HTMLParseError('unexpected end of html')
class HTMLAttributeParser(compat_HTMLParser):
"""Trivial HTML parser to gather the attributes for a single element"""