-
Notifications
You must be signed in to change notification settings - Fork 114
/
w3cmicrodata.py
250 lines (210 loc) · 8.15 KB
/
w3cmicrodata.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
# mypy: disallow_untyped_defs=False
"""
HTML Microdata parser
Piece of code extracted form:
* http://blog.scrapinghub.com/2014/06/18/extracting-schema-org-microdata-using-scrapy-selectors-and-xpath/
Ported to lxml
follows http://www.w3.org/TR/microdata/#json
"""
from __future__ import annotations
import collections
from functools import partial
from typing import Any, Set
try:
from urlparse import urljoin
except ImportError:
from urllib.parse import urljoin
import html_text
import lxml.etree
from lxml.html.clean import Cleaner
from w3lib.html import strip_html5_whitespace
from extruct.utils import parse_html
# Cleaner which is similar to html_text cleaner, but is less aggressive
cleaner = Cleaner(
scripts=True,
javascript=False, # onclick attributes are fine
comments=True,
style=True,
links=True,
meta=True,
page_structure=False, # <title> may be nice to have
processing_instructions=True,
embedded=False, # keep embedded content
frames=False, # keep frames
forms=False, # keep forms
annoying_tags=False,
remove_unknown_tags=False,
safe_attrs_only=False,
)
class LxmlMicrodataExtractor:
# iterate in document order (used below for fast get_docid)
_xp_item = lxml.etree.XPath("descendant-or-self::*[@itemscope]")
_xp_prop = lxml.etree.XPath(
"""set:difference(
.//*[@itemprop],
.//*[@itemscope]//*[@itemprop])""",
namespaces={"set": "http://exslt.org/sets"},
)
_xp_clean_text = lxml.etree.XPath(
"descendant-or-self::*[not(self::script or self::style)]/text()"
)
def __init__(
self, nested=True, strict=False, add_text_content=False, add_html_node=False
):
self.nested = nested
self.strict = strict
self.add_text_content = add_text_content
self.add_html_node = add_html_node
def extract(self, htmlstring, base_url=None, encoding="UTF-8"):
tree = parse_html(htmlstring, encoding=encoding)
return self.extract_items(tree, base_url)
def extract_items(self, document, base_url):
itemids = self._build_itemids(document)
items_seen: Set[Any] = set()
return [
item
for item in (
self._extract_item(
it, items_seen=items_seen, base_url=base_url, itemids=itemids
)
for it in self._xp_item(document) # type: ignore[union-attr]
)
if item
]
def get_docid(self, node, itemids):
return itemids[node]
def _build_itemids(self, document):
"""Build itemids for a fast get_docid implementation. Use document order."""
root = document.getroottree().getroot()
return {node: idx + 1 for idx, node in enumerate(self._xp_item(root))} # type: ignore[arg-type]
def _extract_item(self, node, items_seen, base_url, itemids):
itemid = self.get_docid(node, itemids)
if self.nested:
if itemid in items_seen:
return
items_seen.add(itemid)
item = {}
if not self.nested:
item["iid"] = itemid
types = node.get("itemtype", "").split()
if types:
if not self.strict and len(types) == 1:
item["type"] = types[0]
else:
item["type"] = types
nodeid = node.get("itemid")
if nodeid:
item["id"] = nodeid.strip()
properties = collections.defaultdict(list)
for name, value in self._extract_properties(
node, items_seen=items_seen, base_url=base_url, itemids=itemids
):
properties[name].append(value)
# process item references
refs = node.get("itemref", "").split()
if refs:
for refid in refs:
for name, value in self._extract_property_refs(
node,
refid,
items_seen=items_seen,
base_url=base_url,
itemids=itemids,
):
properties[name].append(value)
props = []
for (name, values) in properties.items():
if not self.strict and len(values) == 1:
props.append((name, values[0]))
else:
props.append((name, values))
if props:
item["properties"] = dict(props)
else:
# item without properties; let's use the node itself
item["value"] = self._extract_property_value(
node,
force=True,
items_seen=items_seen,
base_url=base_url,
itemids=itemids,
)
# below are not in the specs, but can be handy
if self.add_text_content:
textContent = self._extract_textContent(node)
if textContent:
item["textContent"] = textContent
if self.add_html_node:
item["htmlNode"] = node
return item
def _extract_properties(self, node, items_seen, base_url, itemids):
for prop in self._xp_prop(node): # type: ignore[union-attr]
yield from self._extract_property(
prop, items_seen=items_seen, base_url=base_url, itemids=itemids
)
def _extract_property_refs(self, node, refid, items_seen, base_url, itemids):
ref_node = node.xpath("id($refid)[1]", refid=refid)
if not ref_node:
return
ref_node = ref_node[0]
extract_fn = partial(
self._extract_property,
items_seen=items_seen,
base_url=base_url,
itemids=itemids,
)
if "itemprop" in ref_node.keys() and "itemscope" in ref_node.keys():
# An full item will be extracted from the node, no need to look
# for individual properties in child nodes
yield from extract_fn(ref_node)
else:
base_parent_scope = ref_node.xpath("ancestor-or-self::*[@itemscope][1]")
for prop in ref_node.xpath("descendant-or-self::*[@itemprop]"):
parent_scope = prop.xpath("ancestor::*[@itemscope][1]")
# Skip properties defined in a different scope than the ref_node
if parent_scope == base_parent_scope:
yield from extract_fn(prop)
def _extract_property(self, node, items_seen, base_url, itemids):
props = node.get("itemprop").split()
value = self._extract_property_value(
node, items_seen=items_seen, base_url=base_url, itemids=itemids
)
return [(p, value) for p in props]
def _extract_property_value(self, node, items_seen, base_url, itemids, force=False):
# http://www.w3.org/TR/microdata/#values
if not force and node.get("itemscope") is not None:
if self.nested:
return self._extract_item(
node, items_seen=items_seen, base_url=base_url, itemids=itemids
)
else:
return {"iid_ref": self.get_docid(node, itemids)}
elif node.tag == "meta":
return node.get("content", "")
elif node.tag in (
"audio",
"embed",
"iframe",
"img",
"source",
"track",
"video",
):
return urljoin(base_url, strip_html5_whitespace(node.get("src", "")))
elif node.tag in ("a", "area", "link"):
return urljoin(base_url, strip_html5_whitespace(node.get("href", "")))
elif node.tag in ("object",):
return urljoin(base_url, strip_html5_whitespace(node.get("data", "")))
elif node.tag in ("data", "meter"):
return node.get("value", "")
elif node.tag in ("time",):
return node.get("datetime", "")
# not in W3C specs but used in schema.org examples
elif node.get("content"):
return node.get("content")
else:
return self._extract_textContent(node)
def _extract_textContent(self, node):
clean_node = cleaner.clean_html(node)
return html_text.etree_to_text(clean_node)
MicrodataExtractor = LxmlMicrodataExtractor