Python code coverage for Lib/xml/etree/ElementPath.py

#	count	content
1	n/a	#
2	n/a	# ElementTree
3	n/a	# $Id: ElementPath.py 3375 2008-02-13 08:05:08Z fredrik $
4	n/a	#
5	n/a	# limited xpath support for element trees
6	n/a	#
7	n/a	# history:
8	n/a	# 2003-05-23 fl created
9	n/a	# 2003-05-28 fl added support for // etc
10	n/a	# 2003-08-27 fl fixed parsing of periods in element names
11	n/a	# 2007-09-10 fl new selection engine
12	n/a	# 2007-09-12 fl fixed parent selector
13	n/a	# 2007-09-13 fl added iterfind; changed findall to return a list
14	n/a	# 2007-11-30 fl added namespaces support
15	n/a	# 2009-10-30 fl added child element value filter
16	n/a	#
17	n/a	# Copyright (c) 2003-2009 by Fredrik Lundh. All rights reserved.
18	n/a	#
19	n/a	# fredrik@pythonware.com
20	n/a	# http://www.pythonware.com
21	n/a	#
22	n/a	# --------------------------------------------------------------------
23	n/a	# The ElementTree toolkit is
24	n/a	#
25	n/a	# Copyright (c) 1999-2009 by Fredrik Lundh
26	n/a	#
27	n/a	# By obtaining, using, and/or copying this software and/or its
28	n/a	# associated documentation, you agree that you have read, understood,
29	n/a	# and will comply with the following terms and conditions:
30	n/a	#
31	n/a	# Permission to use, copy, modify, and distribute this software and
32	n/a	# its associated documentation for any purpose and without fee is
33	n/a	# hereby granted, provided that the above copyright notice appears in
34	n/a	# all copies, and that both that copyright notice and this permission
35	n/a	# notice appear in supporting documentation, and that the name of
36	n/a	# Secret Labs AB or the author not be used in advertising or publicity
37	n/a	# pertaining to distribution of the software without specific, written
38	n/a	# prior permission.
39	n/a	#
40	n/a	# SECRET LABS AB AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
41	n/a	# TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANT-
42	n/a	# ABILITY AND FITNESS. IN NO EVENT SHALL SECRET LABS AB OR THE AUTHOR
43	n/a	# BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY
44	n/a	# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
45	n/a	# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
46	n/a	# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
47	n/a	# OF THIS SOFTWARE.
48	n/a	# --------------------------------------------------------------------
49	n/a
50	n/a	# Licensed to PSF under a Contributor Agreement.
51	n/a	# See http://www.python.org/psf/license for licensing details.
52	n/a
53	n/a	##
54	n/a	# Implementation module for XPath support. There's usually no reason
55	n/a	# to import this module directly; the <b>ElementTree</b> does this for
56	n/a	# you, if needed.
57	n/a	##
58	n/a
59	n/a	import re
60	n/a
61	n/a	xpath_tokenizer_re = re.compile(
62	n/a	r"("
63	n/a	r"'[^']'\|\"[^\"]\"\|"
64	n/a	r"::\|"
65	n/a	r"//?\|"
66	n/a	r"\.\.\|"
67	n/a	r"\|"
68	n/a	r"[/.*:\[\]@=])\|"
69	n/a	r"((?:\{[^}]+\})?[^/\[\]@=\s]+)\|"
70	n/a	r"\s+"
71	n/a	)
72	n/a
73	n/a	def xpath_tokenizer(pattern, namespaces=None):
74	n/a	for token in xpath_tokenizer_re.findall(pattern):
75	n/a	tag = token[1]
76	n/a	if tag and tag[0] != "{" and ":" in tag:
77	n/a	try:
78	n/a	prefix, uri = tag.split(":", 1)
79	n/a	if not namespaces:
80	n/a	raise KeyError
81	n/a	yield token[0], "{%s}%s" % (namespaces[prefix], uri)
82	n/a	except KeyError:
83	n/a	raise SyntaxError("prefix %r not found in prefix map" % prefix)
84	n/a	else:
85	n/a	yield token
86	n/a
87	n/a	def get_parent_map(context):
88	n/a	parent_map = context.parent_map
89	n/a	if parent_map is None:
90	n/a	context.parent_map = parent_map = {}
91	n/a	for p in context.root.iter():
92	n/a	for e in p:
93	n/a	parent_map[e] = p
94	n/a	return parent_map
95	n/a
96	n/a	def prepare_child(next, token):
97	n/a	tag = token[1]
98	n/a	def select(context, result):
99	n/a	for elem in result:
100	n/a	for e in elem:
101	n/a	if e.tag == tag:
102	n/a	yield e
103	n/a	return select
104	n/a
105	n/a	def prepare_star(next, token):
106	n/a	def select(context, result):
107	n/a	for elem in result:
108	n/a	yield from elem
109	n/a	return select
110	n/a
111	n/a	def prepare_self(next, token):
112	n/a	def select(context, result):
113	n/a	yield from result
114	n/a	return select
115	n/a
116	n/a	def prepare_descendant(next, token):
117	n/a	try:
118	n/a	token = next()
119	n/a	except StopIteration:
120	n/a	return
121	n/a	if token[0] == "*":
122	n/a	tag = "*"
123	n/a	elif not token[0]:
124	n/a	tag = token[1]
125	n/a	else:
126	n/a	raise SyntaxError("invalid descendant")
127	n/a	def select(context, result):
128	n/a	for elem in result:
129	n/a	for e in elem.iter(tag):
130	n/a	if e is not elem:
131	n/a	yield e
132	n/a	return select
133	n/a
134	n/a	def prepare_parent(next, token):
135	n/a	def select(context, result):
136	n/a	# FIXME: raise error if .. is applied at toplevel?
137	n/a	parent_map = get_parent_map(context)
138	n/a	result_map = {}
139	n/a	for elem in result:
140	n/a	if elem in parent_map:
141	n/a	parent = parent_map[elem]
142	n/a	if parent not in result_map:
143	n/a	result_map[parent] = None
144	n/a	yield parent
145	n/a	return select
146	n/a
147	n/a	def prepare_predicate(next, token):
148	n/a	# FIXME: replace with real parser!!! refs:
149	n/a	# http://effbot.org/zone/simple-iterator-parser.htm
150	n/a	# http://javascript.crockford.com/tdop/tdop.html
151	n/a	signature = []
152	n/a	predicate = []
153	n/a	while 1:
154	n/a	try:
155	n/a	token = next()
156	n/a	except StopIteration:
157	n/a	return
158	n/a	if token[0] == "]":
159	n/a	break
160	n/a	if token[0] and token[0][:1] in "'\"":
161	n/a	token = "'", token[0][1:-1]
162	n/a	signature.append(token[0] or "-")
163	n/a	predicate.append(token[1])
164	n/a	signature = "".join(signature)
165	n/a	# use signature to determine predicate type
166	n/a	if signature == "@-":
167	n/a	# [@attribute] predicate
168	n/a	key = predicate[1]
169	n/a	def select(context, result):
170	n/a	for elem in result:
171	n/a	if elem.get(key) is not None:
172	n/a	yield elem
173	n/a	return select
174	n/a	if signature == "@-='":
175	n/a	# [@attribute='value']
176	n/a	key = predicate[1]
177	n/a	value = predicate[-1]
178	n/a	def select(context, result):
179	n/a	for elem in result:
180	n/a	if elem.get(key) == value:
181	n/a	yield elem
182	n/a	return select
183	n/a	if signature == "-" and not re.match(r"\-?\d+$", predicate[0]):
184	n/a	# [tag]
185	n/a	tag = predicate[0]
186	n/a	def select(context, result):
187	n/a	for elem in result:
188	n/a	if elem.find(tag) is not None:
189	n/a	yield elem
190	n/a	return select
191	n/a	if signature == "-='" and not re.match(r"\-?\d+$", predicate[0]):
192	n/a	# [tag='value']
193	n/a	tag = predicate[0]
194	n/a	value = predicate[-1]
195	n/a	def select(context, result):
196	n/a	for elem in result:
197	n/a	for e in elem.findall(tag):
198	n/a	if "".join(e.itertext()) == value:
199	n/a	yield elem
200	n/a	break
201	n/a	return select
202	n/a	if signature == "-" or signature == "-()" or signature == "-()-":
203	n/a	# [index] or [last()] or [last()-index]
204	n/a	if signature == "-":
205	n/a	# [index]
206	n/a	index = int(predicate[0]) - 1
207	n/a	if index < 0:
208	n/a	raise SyntaxError("XPath position >= 1 expected")
209	n/a	else:
210	n/a	if predicate[0] != "last":
211	n/a	raise SyntaxError("unsupported function")
212	n/a	if signature == "-()-":
213	n/a	try:
214	n/a	index = int(predicate[2]) - 1
215	n/a	except ValueError:
216	n/a	raise SyntaxError("unsupported expression")
217	n/a	if index > -2:
218	n/a	raise SyntaxError("XPath offset from last() must be negative")
219	n/a	else:
220	n/a	index = -1
221	n/a	def select(context, result):
222	n/a	parent_map = get_parent_map(context)
223	n/a	for elem in result:
224	n/a	try:
225	n/a	parent = parent_map[elem]
226	n/a	# FIXME: what if the selector is "*" ?
227	n/a	elems = list(parent.findall(elem.tag))
228	n/a	if elems[index] is elem:
229	n/a	yield elem
230	n/a	except (IndexError, KeyError):
231	n/a	pass
232	n/a	return select
233	n/a	raise SyntaxError("invalid predicate")
234	n/a
235	n/a	ops = {
236	n/a	"": prepare_child,
237	n/a	"*": prepare_star,
238	n/a	".": prepare_self,
239	n/a	"..": prepare_parent,
240	n/a	"//": prepare_descendant,
241	n/a	"[": prepare_predicate,
242	n/a	}
243	n/a
244	n/a	_cache = {}
245	n/a
246	n/a	class _SelectorContext:
247	n/a	parent_map = None
248	n/a	def __init__(self, root):
249	n/a	self.root = root
250	n/a
251	n/a	# --------------------------------------------------------------------
252	n/a
253	n/a	##
254	n/a	# Generate all matching objects.
255	n/a
256	n/a	def iterfind(elem, path, namespaces=None):
257	n/a	# compile selector pattern
258	n/a	cache_key = (path, None if namespaces is None
259	n/a	else tuple(sorted(namespaces.items())))
260	n/a	if path[-1:] == "/":
261	n/a	path = path + "*" # implicit all (FIXME: keep this?)
262	n/a	try:
263	n/a	selector = _cache[cache_key]
264	n/a	except KeyError:
265	n/a	if len(_cache) > 100:
266	n/a	_cache.clear()
267	n/a	if path[:1] == "/":
268	n/a	raise SyntaxError("cannot use absolute path on element")
269	n/a	next = iter(xpath_tokenizer(path, namespaces)).__next__
270	n/a	try:
271	n/a	token = next()
272	n/a	except StopIteration:
273	n/a	return
274	n/a	selector = []
275	n/a	while 1:
276	n/a	try:
277	n/a	selector.append(ops[token[0]](next, token))
278	n/a	except StopIteration:
279	n/a	raise SyntaxError("invalid path")
280	n/a	try:
281	n/a	token = next()
282	n/a	if token[0] == "/":
283	n/a	token = next()
284	n/a	except StopIteration:
285	n/a	break
286	n/a	_cache[cache_key] = selector
287	n/a	# execute selector pattern
288	n/a	result = [elem]
289	n/a	context = _SelectorContext(elem)
290	n/a	for select in selector:
291	n/a	result = select(context, result)
292	n/a	return result
293	n/a
294	n/a	##
295	n/a	# Find first matching object.
296	n/a
297	n/a	def find(elem, path, namespaces=None):
298	n/a	return next(iterfind(elem, path, namespaces), None)
299	n/a
300	n/a	##
301	n/a	# Find all matching objects.
302	n/a
303	n/a	def findall(elem, path, namespaces=None):
304	n/a	return list(iterfind(elem, path, namespaces))
305	n/a
306	n/a	##
307	n/a	# Find text for first matching object.
308	n/a
309	n/a	def findtext(elem, path, default=None, namespaces=None):
310	n/a	try:
311	n/a	elem = next(iterfind(elem, path, namespaces))
312	n/a	return elem.text or ""
313	n/a	except StopIteration:
314	n/a	return default