# Copyright (c) 2004 Ian Bicking. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in
# the documentation and/or other materials provided with the
# distribution.
#
# 3. Neither the name of Ian Bicking nor the names of its contributors may
# be used to endorse or promote products derived from this software
# without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL IAN BICKING OR
# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
"""The ``lxml.html`` tool set for HTML handling.
"""
from __future__ import absolute_import
__all__ = [
'document_fromstring', 'fragment_fromstring', 'fragments_fromstring', 'fromstring',
'tostring', 'Element', 'defs', 'open_in_browser', 'submit_form',
'find_rel_links', 'find_class', 'make_links_absolute',
'resolve_base_href', 'iterlinks', 'rewrite_links', 'parse']
import copy
import sys
import re
from functools import partial
try:
from collections.abc import MutableMapping, MutableSet
except ImportError:
from collections import MutableMapping, MutableSet
from .. import etree
from . import defs
from ._setmixin import SetMixin
try:
from urlparse import urljoin
except ImportError:
# Python 3
from urllib.parse import urljoin
try:
unicode
except NameError:
# Python 3
unicode = str
try:
basestring
except NameError:
# Python 3
basestring = (str, bytes)
[docs]def __fix_docstring(s):
if not s:
return s
if sys.version_info[0] >= 3:
sub = re.compile(r"^(\s*)u'", re.M).sub
else:
sub = re.compile(r"^(\s*)b'", re.M).sub
return sub(r"\1'", s)
XHTML_NAMESPACE = "http://www.w3.org/1999/xhtml"
_rel_links_xpath = etree.XPath("descendant-or-self::a[@rel]|descendant-or-self::x:a[@rel]",
namespaces={'x':XHTML_NAMESPACE})
_options_xpath = etree.XPath("descendant-or-self::option|descendant-or-self::x:option",
namespaces={'x':XHTML_NAMESPACE})
_forms_xpath = etree.XPath("descendant-or-self::form|descendant-or-self::x:form",
namespaces={'x':XHTML_NAMESPACE})
#_class_xpath = etree.XPath(r"descendant-or-self::*[regexp:match(@class, concat('\b', $class_name, '\b'))]", {'regexp': 'http://exslt.org/regular-expressions'})
_class_xpath = etree.XPath("descendant-or-self::*[@class and contains(concat(' ', normalize-space(@class), ' '), concat(' ', $class_name, ' '))]")
_id_xpath = etree.XPath("descendant-or-self::*[@id=$id]")
_collect_string_content = etree.XPath("string()")
_iter_css_urls = re.compile(r'url\(('+'["][^"]*["]|'+"['][^']*[']|"+r'[^)]*)\)', re.I).finditer
_iter_css_imports = re.compile(r'@import "(.*?)"').finditer
_label_xpath = etree.XPath("//label[@for=$id]|//x:label[@for=$id]",
namespaces={'x':XHTML_NAMESPACE})
_archive_re = re.compile(r'[^ ]+')
_parse_meta_refresh_url = re.compile(
r'[^;=]*;\s*(?:url\s*=\s*)?(?P<url>.*)$', re.I).search
[docs]def _unquote_match(s, pos):
if s[:1] == '"' and s[-1:] == '"' or s[:1] == "'" and s[-1:] == "'":
return s[1:-1], pos+1
else:
return s,pos
[docs]def _nons(tag):
if isinstance(tag, basestring):
if tag[0] == '{' and tag[1:len(XHTML_NAMESPACE)+1] == XHTML_NAMESPACE:
return tag.split('}')[-1]
return tag
[docs]class Classes(MutableSet):
"""Provides access to an element's class attribute as a set-like collection.
Usage::
>>> el = fromstring('<p class="hidden large">Text</p>')
>>> classes = el.classes # or: classes = Classes(el.attrib)
>>> classes |= ['block', 'paragraph']
>>> el.get('class')
'hidden large block paragraph'
>>> classes.toggle('hidden')
False
>>> el.get('class')
'large block paragraph'
>>> classes -= ('some', 'classes', 'block')
>>> el.get('class')
'large paragraph'
"""
def __init__(self, attributes):
self._attributes = attributes
self._get_class_value = partial(attributes.get, 'class', '')
[docs] def add(self, value):
"""
Add a class.
This has no effect if the class is already present.
"""
if not value or re.search(r'\s', value):
raise ValueError("Invalid class name: %r" % value)
classes = self._get_class_value().split()
if value in classes:
return
classes.append(value)
self._attributes['class'] = ' '.join(classes)
[docs] def discard(self, value):
"""
Remove a class if it is currently present.
If the class is not present, do nothing.
"""
if not value or re.search(r'\s', value):
raise ValueError("Invalid class name: %r" % value)
classes = [name for name in self._get_class_value().split()
if name != value]
if classes:
self._attributes['class'] = ' '.join(classes)
elif 'class' in self._attributes:
del self._attributes['class']
[docs] def remove(self, value):
"""
Remove a class; it must currently be present.
If the class is not present, raise a KeyError.
"""
if not value or re.search(r'\s', value):
raise ValueError("Invalid class name: %r" % value)
super(Classes, self).remove(value)
def __contains__(self, name):
classes = self._get_class_value()
return name in classes and name in classes.split()
def __iter__(self):
return iter(self._get_class_value().split())
def __len__(self):
return len(self._get_class_value().split())
# non-standard methods
[docs] def update(self, values):
"""
Add all names from 'values'.
"""
classes = self._get_class_value().split()
extended = False
for value in values:
if value not in classes:
classes.append(value)
extended = True
if extended:
self._attributes['class'] = ' '.join(classes)
[docs] def toggle(self, value):
"""
Add a class name if it isn't there yet, or remove it if it exists.
Returns true if the class was added (and is now enabled) and
false if it was removed (and is now disabled).
"""
if not value or re.search(r'\s', value):
raise ValueError("Invalid class name: %r" % value)
classes = self._get_class_value().split()
try:
classes.remove(value)
enabled = False
except ValueError:
classes.append(value)
enabled = True
if classes:
self._attributes['class'] = ' '.join(classes)
else:
del self._attributes['class']
return enabled
[docs]class HtmlMixin(object):
[docs] def set(self, key, value=None):
"""set(self, key, value=None)
Sets an element attribute. If no value is provided, or if the value is None,
creates a 'boolean' attribute without value, e.g. "<form novalidate></form>"
for ``form.set('novalidate')``.
"""
super(HtmlMixin, self).set(key, value)
@property
def classes(self):
"""
A set-like wrapper around the 'class' attribute.
"""
return Classes(self.attrib)
@classes.setter
def classes(self, classes):
assert isinstance(classes, Classes) # only allow "el.classes |= ..." etc.
value = classes._get_class_value()
if value:
self.set('class', value)
elif self.get('class') is not None:
del self.attrib['class']
@property
def base_url(self):
"""
Returns the base URL, given when the page was parsed.
Use with ``urlparse.urljoin(el.base_url, href)`` to get
absolute URLs.
"""
return self.getroottree().docinfo.URL
@property
def forms(self):
"""
Return a list of all the forms
"""
return _forms_xpath(self)
@property
def body(self):
"""
Return the <body> element. Can be called from a child element
to get the document's head.
"""
return self.xpath('//body|//x:body', namespaces={'x':XHTML_NAMESPACE})[0]
@property
def head(self):
"""
Returns the <head> element. Can be called from a child
element to get the document's head.
"""
return self.xpath('//head|//x:head', namespaces={'x':XHTML_NAMESPACE})[0]
@property
def label(self):
"""
Get or set any <label> element associated with this element.
"""
id = self.get('id')
if not id:
return None
result = _label_xpath(self, id=id)
if not result:
return None
else:
return result[0]
@label.setter
def label(self, label):
id = self.get('id')
if not id:
raise TypeError(
"You cannot set a label for an element (%r) that has no id"
% self)
if _nons(label.tag) != 'label':
raise TypeError(
"You can only assign label to a label element (not %r)"
% label)
label.set('for', id)
@label.deleter
def label(self):
label = self.label
if label is not None:
del label.attrib['for']
[docs] def drop_tree(self):
"""
Removes this element from the tree, including its children and
text. The tail text is joined to the previous element or
parent.
"""
parent = self.getparent()
assert parent is not None
if self.tail:
previous = self.getprevious()
if previous is None:
parent.text = (parent.text or '') + self.tail
else:
previous.tail = (previous.tail or '') + self.tail
parent.remove(self)
[docs] def drop_tag(self):
"""
Remove the tag, but not its children or text. The children and text
are merged into the parent.
Example::
>>> h = fragment_fromstring('<div>Hello <b>World!</b></div>')
>>> h.find('.//b').drop_tag()
>>> print(tostring(h, encoding='unicode'))
<div>Hello World!</div>
"""
parent = self.getparent()
assert parent is not None
previous = self.getprevious()
if self.text and isinstance(self.tag, basestring):
# not a Comment, etc.
if previous is None:
parent.text = (parent.text or '') + self.text
else:
previous.tail = (previous.tail or '') + self.text
if self.tail:
if len(self):
last = self[-1]
last.tail = (last.tail or '') + self.tail
elif previous is None:
parent.text = (parent.text or '') + self.tail
else:
previous.tail = (previous.tail or '') + self.tail
index = parent.index(self)
parent[index:index+1] = self[:]
[docs] def find_rel_links(self, rel):
"""
Find any links like ``<a rel="{rel}">...</a>``; returns a list of elements.
"""
rel = rel.lower()
return [el for el in _rel_links_xpath(self)
if el.get('rel').lower() == rel]
[docs] def find_class(self, class_name):
"""
Find any elements with the given class name.
"""
return _class_xpath(self, class_name=class_name)
[docs] def get_element_by_id(self, id, *default):
"""
Get the first element in a document with the given id. If none is
found, return the default argument if provided or raise KeyError
otherwise.
Note that there can be more than one element with the same id,
and this isn't uncommon in HTML documents found in the wild.
Browsers return only the first match, and this function does
the same.
"""
try:
# FIXME: should this check for multiple matches?
# browsers just return the first one
return _id_xpath(self, id=id)[0]
except IndexError:
if default:
return default[0]
else:
raise KeyError(id)
[docs] def text_content(self):
"""
Return the text content of the tag (and the text in any children).
"""
return _collect_string_content(self)
[docs] def cssselect(self, expr, translator='html'):
"""
Run the CSS expression on this element and its children,
returning a list of the results.
Equivalent to lxml.cssselect.CSSSelect(expr, translator='html')(self)
-- note that pre-compiling the expression can provide a substantial
speedup.
"""
# Do the import here to make the dependency optional.
from lxml.cssselect import CSSSelector
return CSSSelector(expr, translator=translator)(self)
########################################
## Link functions
########################################
[docs] def make_links_absolute(self, base_url=None, resolve_base_href=True,
handle_failures=None):
"""
Make all links in the document absolute, given the
``base_url`` for the document (the full URL where the document
came from), or if no ``base_url`` is given, then the ``.base_url``
of the document.
If ``resolve_base_href`` is true, then any ``<base href>``
tags in the document are used *and* removed from the document.
If it is false then any such tag is ignored.
If ``handle_failures`` is None (default), a failure to process
a URL will abort the processing. If set to 'ignore', errors
are ignored. If set to 'discard', failing URLs will be removed.
"""
if base_url is None:
base_url = self.base_url
if base_url is None:
raise TypeError(
"No base_url given, and the document has no base_url")
if resolve_base_href:
self.resolve_base_href()
if handle_failures == 'ignore':
def link_repl(href):
try:
return urljoin(base_url, href)
except ValueError:
return href
elif handle_failures == 'discard':
def link_repl(href):
try:
return urljoin(base_url, href)
except ValueError:
return None
elif handle_failures is None:
def link_repl(href):
return urljoin(base_url, href)
else:
raise ValueError(
"unexpected value for handle_failures: %r" % handle_failures)
self.rewrite_links(link_repl)
[docs] def resolve_base_href(self, handle_failures=None):
"""
Find any ``<base href>`` tag in the document, and apply its
values to all links found in the document. Also remove the
tag once it has been applied.
If ``handle_failures`` is None (default), a failure to process
a URL will abort the processing. If set to 'ignore', errors
are ignored. If set to 'discard', failing URLs will be removed.
"""
base_href = None
basetags = self.xpath('//base[@href]|//x:base[@href]',
namespaces={'x': XHTML_NAMESPACE})
for b in basetags:
base_href = b.get('href')
b.drop_tree()
if not base_href:
return
self.make_links_absolute(base_href, resolve_base_href=False,
handle_failures=handle_failures)
[docs] def iterlinks(self):
"""
Yield (element, attribute, link, pos), where attribute may be None
(indicating the link is in the text). ``pos`` is the position
where the link occurs; often 0, but sometimes something else in
the case of links in stylesheets or style tags.
Note: <base href> is *not* taken into account in any way. The
link you get is exactly the link in the document.
Note: multiple links inside of a single text string or
attribute value are returned in reversed order. This makes it
possible to replace or delete them from the text string value
based on their reported text positions. Otherwise, a
modification at one text position can change the positions of
links reported later on.
"""
link_attrs = defs.link_attrs
for el in self.iter(etree.Element):
attribs = el.attrib
tag = _nons(el.tag)
if tag == 'object':
codebase = None
## <object> tags have attributes that are relative to
## codebase
if 'codebase' in attribs:
codebase = el.get('codebase')
yield (el, 'codebase', codebase, 0)
for attrib in ('classid', 'data'):
if attrib in attribs:
value = el.get(attrib)
if codebase is not None:
value = urljoin(codebase, value)
yield (el, attrib, value, 0)
if 'archive' in attribs:
for match in _archive_re.finditer(el.get('archive')):
value = match.group(0)
if codebase is not None:
value = urljoin(codebase, value)
yield (el, 'archive', value, match.start())
else:
for attrib in link_attrs:
if attrib in attribs:
yield (el, attrib, attribs[attrib], 0)
if tag == 'meta':
http_equiv = attribs.get('http-equiv', '').lower()
if http_equiv == 'refresh':
content = attribs.get('content', '')
match = _parse_meta_refresh_url(content)
url = (match.group('url') if match else content).strip()
# unexpected content means the redirect won't work, but we might
# as well be permissive and return the entire string.
if url:
url, pos = _unquote_match(
url, match.start('url') if match else content.find(url))
yield (el, 'content', url, pos)
elif tag == 'param':
valuetype = el.get('valuetype') or ''
if valuetype.lower() == 'ref':
## FIXME: while it's fine we *find* this link,
## according to the spec we aren't supposed to
## actually change the value, including resolving
## it. It can also still be a link, even if it
## doesn't have a valuetype="ref" (which seems to be the norm)
## http://www.w3.org/TR/html401/struct/objects.html#adef-valuetype
yield (el, 'value', el.get('value'), 0)
elif tag == 'style' and el.text:
urls = [
# (start_pos, url)
_unquote_match(match.group(1), match.start(1))[::-1]
for match in _iter_css_urls(el.text)
] + [
(match.start(1), match.group(1))
for match in _iter_css_imports(el.text)
]
if urls:
# sort by start pos to bring both match sets back into order
# and reverse the list to report correct positions despite
# modifications
urls.sort(reverse=True)
for start, url in urls:
yield (el, None, url, start)
if 'style' in attribs:
urls = list(_iter_css_urls(attribs['style']))
if urls:
# return in reversed order to simplify in-place modifications
for match in urls[::-1]:
url, start = _unquote_match(match.group(1), match.start(1))
yield (el, 'style', url, start)
[docs] def rewrite_links(self, link_repl_func, resolve_base_href=True,
base_href=None):
"""
Rewrite all the links in the document. For each link
``link_repl_func(link)`` will be called, and the return value
will replace the old link.
Note that links may not be absolute (unless you first called
``make_links_absolute()``), and may be internal (e.g.,
``'#anchor'``). They can also be values like
``'mailto:email'`` or ``'javascript:expr'``.
If you give ``base_href`` then all links passed to
``link_repl_func()`` will take that into account.
If the ``link_repl_func`` returns None, the attribute or
tag text will be removed completely.
"""
if base_href is not None:
# FIXME: this can be done in one pass with a wrapper
# around link_repl_func
self.make_links_absolute(
base_href, resolve_base_href=resolve_base_href)
elif resolve_base_href:
self.resolve_base_href()
for el, attrib, link, pos in self.iterlinks():
new_link = link_repl_func(link.strip())
if new_link == link:
continue
if new_link is None:
# Remove the attribute or element content
if attrib is None:
el.text = ''
else:
del el.attrib[attrib]
continue
if attrib is None:
new = el.text[:pos] + new_link + el.text[pos+len(link):]
el.text = new
else:
cur = el.get(attrib)
if not pos and len(cur) == len(link):
new = new_link # most common case
else:
new = cur[:pos] + new_link + cur[pos+len(link):]
el.set(attrib, new)
[docs]class _MethodFunc(object):
"""
An object that represents a method on an element as a function;
the function takes either an element or an HTML string. It
returns whatever the function normally returns, or if the function
works in-place (and so returns None) it returns a serialized form
of the resulting document.
"""
def __init__(self, name, copy=False, source_class=HtmlMixin):
self.name = name
self.copy = copy
self.__doc__ = getattr(source_class, self.name).__doc__
def __call__(self, doc, *args, **kw):
result_type = type(doc)
if isinstance(doc, basestring):
if 'copy' in kw:
raise TypeError(
"The keyword 'copy' can only be used with element inputs to %s, not a string input" % self.name)
doc = fromstring(doc, **kw)
else:
if 'copy' in kw:
make_a_copy = kw.pop('copy')
else:
make_a_copy = self.copy
if make_a_copy:
doc = copy.deepcopy(doc)
meth = getattr(doc, self.name)
result = meth(*args, **kw)
# FIXME: this None test is a bit sloppy
if result is None:
# Then return what we got in
return _transform_result(result_type, doc)
else:
return result
find_rel_links = _MethodFunc('find_rel_links', copy=False)
find_class = _MethodFunc('find_class', copy=False)
make_links_absolute = _MethodFunc('make_links_absolute', copy=True)
resolve_base_href = _MethodFunc('resolve_base_href', copy=True)
iterlinks = _MethodFunc('iterlinks', copy=False)
rewrite_links = _MethodFunc('rewrite_links', copy=True)
[docs]class HtmlElement(HtmlMixin, etree.ElementBase):
pass
[docs]class HtmlProcessingInstruction(HtmlMixin, etree.PIBase):
pass
[docs]class HtmlEntity(HtmlMixin, etree.EntityBase):
pass
[docs]class HtmlElementClassLookup(etree.CustomElementClassLookup):
"""A lookup scheme for HTML Element classes.
To create a lookup instance with different Element classes, pass a tag
name mapping of Element classes in the ``classes`` keyword argument and/or
a tag name mapping of Mixin classes in the ``mixins`` keyword argument.
The special key '*' denotes a Mixin class that should be mixed into all
Element classes.
"""
_default_element_classes = {}
def __init__(self, classes=None, mixins=None):
etree.CustomElementClassLookup.__init__(self)
if classes is None:
classes = self._default_element_classes.copy()
if mixins:
mixers = {}
for name, value in mixins:
if name == '*':
for n in classes.keys():
mixers.setdefault(n, []).append(value)
else:
mixers.setdefault(name, []).append(value)
for name, mix_bases in mixers.items():
cur = classes.get(name, HtmlElement)
bases = tuple(mix_bases + [cur])
classes[name] = type(cur.__name__, bases, {})
self._element_classes = classes
[docs] def lookup(self, node_type, document, namespace, name):
if node_type == 'element':
return self._element_classes.get(name.lower(), HtmlElement)
elif node_type == 'comment':
return HtmlComment
elif node_type == 'PI':
return HtmlProcessingInstruction
elif node_type == 'entity':
return HtmlEntity
# Otherwise normal lookup
return None
################################################################################
# parsing
################################################################################
_looks_like_full_html_unicode = re.compile(
unicode(r'^\s*<(?:html|!doctype)'), re.I).match
_looks_like_full_html_bytes = re.compile(
r'^\s*<(?:html|!doctype)'.encode('ascii'), re.I).match
[docs]def document_fromstring(html, parser=None, ensure_head_body=False, **kw):
if parser is None:
parser = html_parser
value = etree.fromstring(html, parser, **kw)
if value is None:
raise etree.ParserError(
"Document is empty")
if ensure_head_body and value.find('head') is None:
value.insert(0, Element('head'))
if ensure_head_body and value.find('body') is None:
value.append(Element('body'))
return value
[docs]def fragments_fromstring(html, no_leading_text=False, base_url=None,
parser=None, **kw):
"""Parses several HTML elements, returning a list of elements.
The first item in the list may be a string.
If no_leading_text is true, then it will be an error if there is
leading text, and it will always be a list of only elements.
base_url will set the document's base_url attribute
(and the tree's docinfo.URL).
"""
if parser is None:
parser = html_parser
# FIXME: check what happens when you give html with a body, head, etc.
if isinstance(html, bytes):
if not _looks_like_full_html_bytes(html):
# can't use %-formatting in early Py3 versions
html = ('<html><body>'.encode('ascii') + html +
'</body></html>'.encode('ascii'))
else:
if not _looks_like_full_html_unicode(html):
html = '<html><body>%s</body></html>' % html
doc = document_fromstring(html, parser=parser, base_url=base_url, **kw)
assert _nons(doc.tag) == 'html'
bodies = [e for e in doc if _nons(e.tag) == 'body']
assert len(bodies) == 1, ("too many bodies: %r in %r" % (bodies, html))
body = bodies[0]
elements = []
if no_leading_text and body.text and body.text.strip():
raise etree.ParserError(
"There is leading text: %r" % body.text)
if body.text and body.text.strip():
elements.append(body.text)
elements.extend(body)
# FIXME: removing the reference to the parent artificial document
# would be nice
return elements
[docs]def fragment_fromstring(html, create_parent=False, base_url=None,
parser=None, **kw):
"""
Parses a single HTML element; it is an error if there is more than
one element, or if anything but whitespace precedes or follows the
element.
If ``create_parent`` is true (or is a tag name) then a parent node
will be created to encapsulate the HTML in a single element. In this
case, leading or trailing text is also allowed, as are multiple elements
as result of the parsing.
Passing a ``base_url`` will set the document's ``base_url`` attribute
(and the tree's docinfo.URL).
"""
if parser is None:
parser = html_parser
accept_leading_text = bool(create_parent)
elements = fragments_fromstring(
html, parser=parser, no_leading_text=not accept_leading_text,
base_url=base_url, **kw)
if create_parent:
if not isinstance(create_parent, basestring):
create_parent = 'div'
new_root = Element(create_parent)
if elements:
if isinstance(elements[0], basestring):
new_root.text = elements[0]
del elements[0]
new_root.extend(elements)
return new_root
if not elements:
raise etree.ParserError('No elements found')
if len(elements) > 1:
raise etree.ParserError(
"Multiple elements found (%s)"
% ', '.join([_element_name(e) for e in elements]))
el = elements[0]
if el.tail and el.tail.strip():
raise etree.ParserError(
"Element followed by text: %r" % el.tail)
el.tail = None
return el
[docs]def fromstring(html, base_url=None, parser=None, **kw):
"""
Parse the html, returning a single element/document.
This tries to minimally parse the chunk of text, without knowing if it
is a fragment or a document.
base_url will set the document's base_url attribute (and the tree's docinfo.URL)
"""
if parser is None:
parser = html_parser
if isinstance(html, bytes):
is_full_html = _looks_like_full_html_bytes(html)
else:
is_full_html = _looks_like_full_html_unicode(html)
doc = document_fromstring(html, parser=parser, base_url=base_url, **kw)
if is_full_html:
return doc
# otherwise, lets parse it out...
bodies = doc.findall('body')
if not bodies:
bodies = doc.findall('{%s}body' % XHTML_NAMESPACE)
if bodies:
body = bodies[0]
if len(bodies) > 1:
# Somehow there are multiple bodies, which is bad, but just
# smash them into one body
for other_body in bodies[1:]:
if other_body.text:
if len(body):
body[-1].tail = (body[-1].tail or '') + other_body.text
else:
body.text = (body.text or '') + other_body.text
body.extend(other_body)
# We'll ignore tail
# I guess we are ignoring attributes too
other_body.drop_tree()
else:
body = None
heads = doc.findall('head')
if not heads:
heads = doc.findall('{%s}head' % XHTML_NAMESPACE)
if heads:
# Well, we have some sort of structure, so lets keep it all
head = heads[0]
if len(heads) > 1:
for other_head in heads[1:]:
head.extend(other_head)
# We don't care about text or tail in a head
other_head.drop_tree()
return doc
if body is None:
return doc
if (len(body) == 1 and (not body.text or not body.text.strip())
and (not body[-1].tail or not body[-1].tail.strip())):
# The body has just one element, so it was probably a single
# element passed in
return body[0]
# Now we have a body which represents a bunch of tags which have the
# content that was passed in. We will create a fake container, which
# is the body tag, except <body> implies too much structure.
if _contains_block_level_tag(body):
body.tag = 'div'
else:
body.tag = 'span'
return body
[docs]def parse(filename_or_url, parser=None, base_url=None, **kw):
"""
Parse a filename, URL, or file-like object into an HTML document
tree. Note: this returns a tree, not an element. Use
``parse(...).getroot()`` to get the document root.
You can override the base URL with the ``base_url`` keyword. This
is most useful when parsing from a file-like object.
"""
if parser is None:
parser = html_parser
return etree.parse(filename_or_url, parser, base_url=base_url, **kw)
[docs]def _contains_block_level_tag(el):
# FIXME: I could do this with XPath, but would that just be
# unnecessarily slow?
for el in el.iter(etree.Element):
if _nons(el.tag) in defs.block_tags:
return True
return False
[docs]def _element_name(el):
if isinstance(el, etree.CommentBase):
return 'comment'
elif isinstance(el, basestring):
return 'string'
else:
return _nons(el.tag)
################################################################################
# form handling
################################################################################
HtmlElementClassLookup._default_element_classes['form'] = FormElement
[docs]def open_http_urllib(method, url, values):
if not url:
raise ValueError("cannot submit, no URL provided")
## FIXME: should test that it's not a relative URL or something
try:
from urllib import urlencode, urlopen
except ImportError: # Python 3
from urllib.request import urlopen
from urllib.parse import urlencode
if method == 'GET':
if '?' in url:
url += '&'
else:
url += '?'
url += urlencode(values)
data = None
else:
data = urlencode(values)
if not isinstance(data, bytes):
data = data.encode('ASCII')
return urlopen(url, data)
[docs]class FieldsDict(MutableMapping):
def __init__(self, inputs):
self.inputs = inputs
def __getitem__(self, item):
return self.inputs[item].value
def __setitem__(self, item, value):
self.inputs[item].value = value
def __delitem__(self, item):
raise KeyError(
"You cannot remove keys from ElementDict")
[docs] def keys(self):
return self.inputs.keys()
def __contains__(self, item):
return item in self.inputs
def __iter__(self):
return iter(self.inputs.keys())
def __len__(self):
return len(self.inputs)
def __repr__(self):
return '<%s for form %s>' % (
self.__class__.__name__,
self.inputs.form._name())
[docs]class TextareaElement(InputMixin, HtmlElement):
"""
``<textarea>`` element. You can get the name with ``.name`` and
get/set the value with ``.value``
"""
@property
def value(self):
"""
Get/set the value (which is the contents of this element)
"""
content = self.text or ''
if self.tag.startswith("{%s}" % XHTML_NAMESPACE):
serialisation_method = 'xml'
else:
serialisation_method = 'html'
for el in self:
# it's rare that we actually get here, so let's not use ''.join()
content += etree.tostring(
el, method=serialisation_method, encoding='unicode')
return content
@value.setter
def value(self, value):
del self[:]
self.text = value
@value.deleter
def value(self):
self.text = ''
del self[:]
HtmlElementClassLookup._default_element_classes['textarea'] = TextareaElement
[docs]class SelectElement(InputMixin, HtmlElement):
"""
``<select>`` element. You can get the name with ``.name``.
``.value`` will be the value of the selected option, unless this
is a multi-select element (``<select multiple>``), in which case
it will be a set-like object. In either case ``.value_options``
gives the possible values.
The boolean attribute ``.multiple`` shows if this is a
multi-select.
"""
@property
def value(self):
"""
Get/set the value of this select (the selected option).
If this is a multi-select, this is a set-like object that
represents all the selected options.
"""
if self.multiple:
return MultipleSelectOptions(self)
options = _options_xpath(self)
try:
selected_option = next(el for el in reversed(options) if el.get('selected') is not None)
except StopIteration:
try:
selected_option = next(el for el in options if el.get('disabled') is None)
except StopIteration:
return None
value = selected_option.get('value')
if value is None:
value = (selected_option.text or '').strip()
return value
@value.setter
def value(self, value):
if self.multiple:
if isinstance(value, basestring):
raise TypeError("You must pass in a sequence")
values = self.value
values.clear()
values.update(value)
return
checked_option = None
if value is not None:
for el in _options_xpath(self):
opt_value = el.get('value')
if opt_value is None:
opt_value = (el.text or '').strip()
if opt_value == value:
checked_option = el
break
else:
raise ValueError(
"There is no option with the value of %r" % value)
for el in _options_xpath(self):
if 'selected' in el.attrib:
del el.attrib['selected']
if checked_option is not None:
checked_option.set('selected', '')
@value.deleter
def value(self):
# FIXME: should del be allowed at all?
if self.multiple:
self.value.clear()
else:
self.value = None
@property
def value_options(self):
"""
All the possible values this select can have (the ``value``
attribute of all the ``<option>`` elements.
"""
options = []
for el in _options_xpath(self):
value = el.get('value')
if value is None:
value = (el.text or '').strip()
options.append(value)
return options
@property
def multiple(self):
"""
Boolean attribute: is there a ``multiple`` attribute on this element.
"""
return 'multiple' in self.attrib
@multiple.setter
def multiple(self, value):
if value:
self.set('multiple', '')
elif 'multiple' in self.attrib:
del self.attrib['multiple']
HtmlElementClassLookup._default_element_classes['select'] = SelectElement
[docs]class MultipleSelectOptions(SetMixin):
"""
Represents all the selected options in a ``<select multiple>`` element.
You can add to this set-like option to select an option, or remove
to unselect the option.
"""
def __init__(self, select):
self.select = select
@property
def options(self):
"""
Iterator of all the ``<option>`` elements.
"""
return iter(_options_xpath(self.select))
def __iter__(self):
for option in self.options:
if 'selected' in option.attrib:
opt_value = option.get('value')
if opt_value is None:
opt_value = (option.text or '').strip()
yield opt_value
[docs] def add(self, item):
for option in self.options:
opt_value = option.get('value')
if opt_value is None:
opt_value = (option.text or '').strip()
if opt_value == item:
option.set('selected', '')
break
else:
raise ValueError(
"There is no option with the value %r" % item)
[docs] def remove(self, item):
for option in self.options:
opt_value = option.get('value')
if opt_value is None:
opt_value = (option.text or '').strip()
if opt_value == item:
if 'selected' in option.attrib:
del option.attrib['selected']
else:
raise ValueError(
"The option %r is not currently selected" % item)
break
else:
raise ValueError(
"There is not option with the value %r" % item)
def __repr__(self):
return '<%s {%s} for select name=%r>' % (
self.__class__.__name__,
', '.join([repr(v) for v in self]),
self.select.name)
[docs]class RadioGroup(list):
"""
This object represents several ``<input type=radio>`` elements
that have the same name.
You can use this like a list, but also use the property
``.value`` to check/uncheck inputs. Also you can use
``.value_options`` to get the possible values.
"""
@property
def value(self):
"""
Get/set the value, which checks the radio with that value (and
unchecks any other value).
"""
for el in self:
if 'checked' in el.attrib:
return el.get('value')
return None
@value.setter
def value(self, value):
checked_option = None
if value is not None:
for el in self:
if el.get('value') == value:
checked_option = el
break
else:
raise ValueError("There is no radio input with the value %r" % value)
for el in self:
if 'checked' in el.attrib:
del el.attrib['checked']
if checked_option is not None:
checked_option.set('checked', '')
@value.deleter
def value(self):
self.value = None
@property
def value_options(self):
"""
Returns a list of all the possible values.
"""
return [el.get('value') for el in self]
def __repr__(self):
return '%s(%s)' % (
self.__class__.__name__,
list.__repr__(self))
[docs]class CheckboxGroup(list):
"""
Represents a group of checkboxes (``<input type=checkbox>``) that
have the same name.
In addition to using this like a list, the ``.value`` attribute
returns a set-like object that you can add to or remove from to
check and uncheck checkboxes. You can also use ``.value_options``
to get the possible values.
"""
@property
def value(self):
"""
Return a set-like object that can be modified to check or
uncheck individual checkboxes according to their value.
"""
return CheckboxValues(self)
@value.setter
def value(self, value):
values = self.value
values.clear()
if not hasattr(value, '__iter__'):
raise ValueError(
"A CheckboxGroup (name=%r) must be set to a sequence (not %r)"
% (self[0].name, value))
values.update(value)
@value.deleter
def value(self):
self.value.clear()
@property
def value_options(self):
"""
Returns a list of all the possible values.
"""
return [el.get('value') for el in self]
def __repr__(self):
return '%s(%s)' % (
self.__class__.__name__, list.__repr__(self))
[docs]class CheckboxValues(SetMixin):
"""
Represents the values of the checked checkboxes in a group of
checkboxes with the same name.
"""
def __init__(self, group):
self.group = group
def __iter__(self):
return iter([
el.get('value')
for el in self.group
if 'checked' in el.attrib])
[docs] def add(self, value):
for el in self.group:
if el.get('value') == value:
el.set('checked', '')
break
else:
raise KeyError("No checkbox with value %r" % value)
[docs] def remove(self, value):
for el in self.group:
if el.get('value') == value:
if 'checked' in el.attrib:
del el.attrib['checked']
else:
raise KeyError(
"The checkbox with value %r was already unchecked" % value)
break
else:
raise KeyError(
"No checkbox with value %r" % value)
def __repr__(self):
return '<%s {%s} for checkboxes name=%r>' % (
self.__class__.__name__,
', '.join([repr(v) for v in self]),
self.group.name)
HtmlElementClassLookup._default_element_classes['input'] = InputElement
[docs]class LabelElement(HtmlElement):
"""
Represents a ``<label>`` element.
Label elements are linked to other elements with their ``for``
attribute. You can access this element with ``label.for_element``.
"""
@property
def for_element(self):
"""
Get/set the element this label points to. Return None if it
can't be found.
"""
id = self.get('for')
if not id:
return None
return self.body.get_element_by_id(id)
@for_element.setter
def for_element(self, other):
id = other.get('id')
if not id:
raise TypeError(
"Element %r has no id attribute" % other)
self.set('for', id)
@for_element.deleter
def for_element(self):
attrib = self.attrib
if 'id' in attrib:
del attrib['id']
HtmlElementClassLookup._default_element_classes['label'] = LabelElement
############################################################
## Serialization
############################################################
[docs]def html_to_xhtml(html):
"""Convert all tags in an HTML tree to XHTML by moving them to the
XHTML namespace.
"""
try:
html = html.getroot()
except AttributeError:
pass
prefix = "{%s}" % XHTML_NAMESPACE
for el in html.iter(etree.Element):
tag = el.tag
if tag[0] != '{':
el.tag = prefix + tag
[docs]def xhtml_to_html(xhtml):
"""Convert all tags in an XHTML tree to HTML by removing their
XHTML namespace.
"""
try:
xhtml = xhtml.getroot()
except AttributeError:
pass
prefix = "{%s}" % XHTML_NAMESPACE
prefix_len = len(prefix)
for el in xhtml.iter(prefix + "*"):
el.tag = el.tag[prefix_len:]
# This isn't a general match, but it's a match for what libxml2
# specifically serialises:
__str_replace_meta_content_type = re.compile(
r'<meta http-equiv="Content-Type"[^>]*>').sub
__bytes_replace_meta_content_type = re.compile(
r'<meta http-equiv="Content-Type"[^>]*>'.encode('ASCII')).sub
[docs]def tostring(doc, pretty_print=False, include_meta_content_type=False,
encoding=None, method="html", with_tail=True, doctype=None):
"""Return an HTML string representation of the document.
Note: if include_meta_content_type is true this will create a
``<meta http-equiv="Content-Type" ...>`` tag in the head;
regardless of the value of include_meta_content_type any existing
``<meta http-equiv="Content-Type" ...>`` tag will be removed
The ``encoding`` argument controls the output encoding (defaults to
ASCII, with &#...; character references for any characters outside
of ASCII). Note that you can pass the name ``'unicode'`` as
``encoding`` argument to serialise to a Unicode string.
The ``method`` argument defines the output method. It defaults to
'html', but can also be 'xml' for xhtml output, or 'text' to
serialise to plain text without markup.
To leave out the tail text of the top-level element that is being
serialised, pass ``with_tail=False``.
The ``doctype`` option allows passing in a plain string that will
be serialised before the XML tree. Note that passing in non
well-formed content here will make the XML output non well-formed.
Also, an existing doctype in the document tree will not be removed
when serialising an ElementTree instance.
Example::
>>> from lxml import html
>>> root = html.fragment_fromstring('<p>Hello<br>world!</p>')
>>> html.tostring(root)
b'<p>Hello<br>world!</p>'
>>> html.tostring(root, method='html')
b'<p>Hello<br>world!</p>'
>>> html.tostring(root, method='xml')
b'<p>Hello<br/>world!</p>'
>>> html.tostring(root, method='text')
b'Helloworld!'
>>> html.tostring(root, method='text', encoding='unicode')
u'Helloworld!'
>>> root = html.fragment_fromstring('<div><p>Hello<br>world!</p>TAIL</div>')
>>> html.tostring(root[0], method='text', encoding='unicode')
u'Helloworld!TAIL'
>>> html.tostring(root[0], method='text', encoding='unicode', with_tail=False)
u'Helloworld!'
>>> doc = html.document_fromstring('<p>Hello<br>world!</p>')
>>> html.tostring(doc, method='html', encoding='unicode')
u'<html><body><p>Hello<br>world!</p></body></html>'
>>> print(html.tostring(doc, method='html', encoding='unicode',
... doctype='<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"'
... ' "http://www.w3.org/TR/html4/strict.dtd">'))
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html><body><p>Hello<br>world!</p></body></html>
"""
html = etree.tostring(doc, method=method, pretty_print=pretty_print,
encoding=encoding, with_tail=with_tail,
doctype=doctype)
if method == 'html' and not include_meta_content_type:
if isinstance(html, str):
html = __str_replace_meta_content_type('', html)
else:
html = __bytes_replace_meta_content_type(bytes(), html)
return html
tostring.__doc__ = __fix_docstring(tostring.__doc__)
[docs]def open_in_browser(doc, encoding=None):
"""
Open the HTML document in a web browser, saving it to a temporary
file to open it. Note that this does not delete the file after
use. This is mainly meant for debugging.
"""
import os
import webbrowser
import tempfile
if not isinstance(doc, etree._ElementTree):
doc = etree.ElementTree(doc)
handle, fn = tempfile.mkstemp(suffix='.html')
f = os.fdopen(handle, 'wb')
try:
doc.write(f, method="html", encoding=encoding or doc.docinfo.encoding or "UTF-8")
finally:
# we leak the file itself here, but we should at least close it
f.close()
url = 'file://' + fn.replace(os.path.sep, '/')
print(url)
webbrowser.open(url)
################################################################################
# configure Element class lookup
################################################################################
[docs]class HTMLParser(etree.HTMLParser):
"""An HTML parser that is configured to return lxml.html Element
objects.
"""
def __init__(self, **kwargs):
super(HTMLParser, self).__init__(**kwargs)
self.set_element_class_lookup(HtmlElementClassLookup())
[docs]class XHTMLParser(etree.XMLParser):
"""An XML parser that is configured to return lxml.html Element
objects.
Note that this parser is not really XHTML aware unless you let it
load a DTD that declares the HTML entities. To do this, make sure
you have the XHTML DTDs installed in your catalogs, and create the
parser like this::
>>> parser = XHTMLParser(load_dtd=True)
If you additionally want to validate the document, use this::
>>> parser = XHTMLParser(dtd_validation=True)
For catalog support, see http://www.xmlsoft.org/catalog.html.
"""
def __init__(self, **kwargs):
super(XHTMLParser, self).__init__(**kwargs)
self.set_element_class_lookup(HtmlElementClassLookup())
[docs]def Element(*args, **kw):
"""Create a new HTML Element.
This can also be used for XHTML documents.
"""
v = html_parser.makeelement(*args, **kw)
return v
html_parser = HTMLParser()
xhtml_parser = XHTMLParser()