1 """External interface to the BeautifulSoup HTML parser.
2 """
3
4 __all__ = ["fromstring", "parse", "convert_tree"]
5
6 import re
7 from lxml import etree, html
8
9 try:
10 from bs4 import (
11 BeautifulSoup, Tag, Comment, ProcessingInstruction, NavigableString,
12 Declaration, Doctype)
13 _DECLARATION_OR_DOCTYPE = (Declaration, Doctype)
14 except ImportError:
15 from BeautifulSoup import (
16 BeautifulSoup, Tag, Comment, ProcessingInstruction, NavigableString,
17 Declaration)
18 _DECLARATION_OR_DOCTYPE = Declaration
19
20
21 -def fromstring(data, beautifulsoup=None, makeelement=None, **bsargs):
22 """Parse a string of HTML data into an Element tree using the
23 BeautifulSoup parser.
24
25 Returns the root ``<html>`` Element of the tree.
26
27 You can pass a different BeautifulSoup parser through the
28 `beautifulsoup` keyword, and a diffent Element factory function
29 through the `makeelement` keyword. By default, the standard
30 ``BeautifulSoup`` class and the default factory of `lxml.html` are
31 used.
32 """
33 return _parse(data, beautifulsoup, makeelement, **bsargs)
34
35
36 -def parse(file, beautifulsoup=None, makeelement=None, **bsargs):
37 """Parse a file into an ElemenTree using the BeautifulSoup parser.
38
39 You can pass a different BeautifulSoup parser through the
40 `beautifulsoup` keyword, and a diffent Element factory function
41 through the `makeelement` keyword. By default, the standard
42 ``BeautifulSoup`` class and the default factory of `lxml.html` are
43 used.
44 """
45 if not hasattr(file, 'read'):
46 file = open(file)
47 root = _parse(file, beautifulsoup, makeelement, **bsargs)
48 return etree.ElementTree(root)
49
52 """Convert a BeautifulSoup tree to a list of Element trees.
53
54 Returns a list instead of a single root Element to support
55 HTML-like soup with more than one root element.
56
57 You can pass a different Element factory through the `makeelement`
58 keyword.
59 """
60 root = _convert_tree(beautiful_soup_tree, makeelement)
61 children = root.getchildren()
62 for child in children:
63 root.remove(child)
64 return children
65
66
67
68
69 -def _parse(source, beautifulsoup, makeelement, **bsargs):
70 if beautifulsoup is None:
71 beautifulsoup = BeautifulSoup
72 if hasattr(beautifulsoup, "HTML_ENTITIES"):
73 if 'convertEntities' not in bsargs:
74 bsargs['convertEntities'] = 'html'
75 if hasattr(beautifulsoup, "DEFAULT_BUILDER_FEATURES"):
76 if 'features' not in bsargs:
77 bsargs['features'] = 'html.parser'
78 tree = beautifulsoup(source, **bsargs)
79 root = _convert_tree(tree, makeelement)
80
81 if len(root) == 1 and root[0].tag == "html":
82 return root[0]
83 root.tag = "html"
84 return root
85
86
87 _parse_doctype_declaration = re.compile(
88 r'(?:\s|[<!])*DOCTYPE\s*HTML'
89 r'(?:\s+PUBLIC)?(?:\s+(\'[^\']*\'|"[^"]*"))?'
90 r'(?:\s+(\'[^\']*\'|"[^"]*"))?',
91 re.IGNORECASE).match
95
97 self.name = 'html'
98 self.attrs = []
99 self.contents = contents
100
103
106 if makeelement is None:
107 makeelement = html.html_parser.makeelement
108
109
110
111
112
113
114
115 first_element_idx = last_element_idx = None
116 html_root = declaration = None
117 for i, e in enumerate(beautiful_soup_tree):
118 if isinstance(e, Tag):
119 if first_element_idx is None:
120 first_element_idx = i
121 last_element_idx = i
122 if html_root is None and e.name and e.name.lower() == 'html':
123 html_root = e
124 elif declaration is None and isinstance(e, _DECLARATION_OR_DOCTYPE):
125 declaration = e
126
127
128
129
130
131
132 if first_element_idx is None:
133 pre_root = post_root = []
134 roots = beautiful_soup_tree.contents
135 else:
136 pre_root = beautiful_soup_tree.contents[:first_element_idx]
137 roots = beautiful_soup_tree.contents[first_element_idx:last_element_idx+1]
138 post_root = beautiful_soup_tree.contents[last_element_idx+1:]
139
140
141 if html_root is not None:
142
143 i = roots.index(html_root)
144 html_root.contents = roots[:i] + html_root.contents + roots[i+1:]
145 else:
146
147 html_root = _PseudoTag(roots)
148
149 convert_node = _init_node_converters(makeelement)
150
151
152 res_root = convert_node(html_root)
153 prev = res_root
154 for e in reversed(pre_root):
155 converted = convert_node(e)
156 if converted is not None:
157 prev.addprevious(converted)
158 prev = converted
159
160
161 prev = res_root
162 for e in post_root:
163 converted = convert_node(e)
164 if converted is not None:
165 prev.addnext(converted)
166 prev = converted
167
168 if declaration is not None:
169 try:
170
171 doctype_string = declaration.output_ready()
172 except AttributeError:
173 doctype_string = declaration.string
174
175 match = _parse_doctype_declaration(doctype_string)
176 if not match:
177
178
179 pass
180 else:
181 external_id, sys_uri = match.groups()
182 docinfo = res_root.getroottree().docinfo
183
184 docinfo.public_id = external_id and external_id[1:-1]
185 docinfo.system_url = sys_uri and sys_uri[1:-1]
186
187 return res_root
188
191 converters = {}
192 ordered_node_types = []
193
194 def converter(*types):
195 def add(handler):
196 for t in types:
197 converters[t] = handler
198 ordered_node_types.append(t)
199 return handler
200 return add
201
202 def find_best_converter(node):
203 for t in ordered_node_types:
204 if isinstance(node, t):
205 return converters[t]
206 return None
207
208 def convert_node(bs_node, parent=None):
209
210 try:
211 handler = converters[type(bs_node)]
212 except KeyError:
213 handler = converters[type(bs_node)] = find_best_converter(bs_node)
214 if handler is None:
215 return None
216 return handler(bs_node, parent)
217
218 def map_attrs(bs_attrs):
219 if isinstance(bs_attrs, dict):
220 attribs = {}
221 for k, v in bs_attrs.items():
222 if isinstance(v, list):
223 v = " ".join(v)
224 attribs[k] = unescape(v)
225 else:
226 attribs = dict((k, unescape(v)) for k, v in bs_attrs)
227 return attribs
228
229 def append_text(parent, text):
230 if len(parent) == 0:
231 parent.text = (parent.text or '') + text
232 else:
233 parent[-1].tail = (parent[-1].tail or '') + text
234
235
236
237 @converter(Tag, _PseudoTag)
238 def convert_tag(bs_node, parent):
239 attrs = bs_node.attrs
240 if parent is not None:
241 attribs = map_attrs(attrs) if attrs else None
242 res = etree.SubElement(parent, bs_node.name, attrib=attribs)
243 else:
244 attribs = map_attrs(attrs) if attrs else {}
245 res = makeelement(bs_node.name, attrib=attribs)
246
247 for child in bs_node:
248
249 try:
250 handler = converters[type(child)]
251 except KeyError:
252 pass
253 else:
254 if handler is not None:
255 handler(child, res)
256 continue
257 convert_node(child, res)
258 return res
259
260 @converter(Comment)
261 def convert_comment(bs_node, parent):
262 res = html.HtmlComment(bs_node)
263 if parent is not None:
264 parent.append(res)
265 return res
266
267 @converter(ProcessingInstruction)
268 def convert_pi(bs_node, parent):
269 if bs_node.endswith('?'):
270
271
272 bs_node = bs_node[:-1]
273 res = etree.ProcessingInstruction(*bs_node.split(' ', 1))
274 if parent is not None:
275 parent.append(res)
276 return res
277
278 @converter(NavigableString)
279 def convert_text(bs_node, parent):
280 if parent is not None:
281 append_text(parent, unescape(bs_node))
282 return None
283
284 return convert_node
285
286
287
288
289 try:
290 from html.entities import name2codepoint
291 except ImportError:
292 from htmlentitydefs import name2codepoint
293
294
295 handle_entities = re.compile(r"&(\w+);").sub
296
297
298 try:
299 unichr
300 except NameError:
301
302 unichr = chr
306 if not string:
307 return ''
308
309 def unescape_entity(m):
310 try:
311 return unichr(name2codepoint[m.group(1)])
312 except KeyError:
313 return m.group(0)
314 return handle_entities(unescape_entity, string)
315