Skip to content
Navigation Menu
{{ message }}
-
Notifications
You must be signed in to change notification settings - Fork 46
Expand file tree
/
Copy pathjsonpointer.py
More file actions
346 lines (249 loc) · 10.3 KB
/
Copy pathjsonpointer.py
File metadata and controls
346 lines (249 loc) · 10.3 KB
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
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
# python-json-pointer - An implementation of the JSON Pointer syntax
# https://github.com/stefankoegl/python-json-pointer
#
# Copyright (c) 2011 Stefan Kögl <stefan@skoegl.net>
# 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. The name of the author may not be used to endorse or promote products
# derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 THE AUTHOR 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.
#
""" Identify specific nodes in a JSON document (RFC 6901) """
# Will be parsed by setup.py to determine package metadata
__author__ = 'Stefan Kögl <stefan@skoegl.net>'
__version__ = '3.1.1'
__website__ = 'https://github.com/stefankoegl/python-json-pointer'
__license__ = 'Modified BSD License'
import copy
import re
from collections.abc import Mapping, Sequence
from itertools import tee, chain
_nothing = object()
def set_pointer(doc, pointer, value, inplace=True):
"""Resolves a pointer against doc and sets the value of the target within doc.
With inplace set to true, doc is modified as long as pointer is not the
root.
>>> obj = {'foo': {'anArray': [ {'prop': 44}], 'another prop': {'baz': 'A string' }}}
>>> set_pointer(obj, '/foo/anArray/0/prop', 55) == \
{'foo': {'another prop': {'baz': 'A string'}, 'anArray': [{'prop': 55}]}}
True
>>> set_pointer(obj, '/foo/yet another prop', 'added prop') == \
{'foo': {'another prop': {'baz': 'A string'}, 'yet another prop': 'added prop', 'anArray': [{'prop': 55}]}}
True
>>> obj = {'foo': {}}
>>> set_pointer(obj, '/foo/a%20b', 'x') == \
{'foo': {'a%20b': 'x' }}
True
"""
pointer = JsonPointer(pointer)
return pointer.set(doc, value, inplace)
def resolve_pointer(doc, pointer, default=_nothing):
""" Resolves pointer against doc and returns the referenced object
>>> obj = {'foo': {'anArray': [ {'prop': 44}], 'another prop': {'baz': 'A string' }}, 'a%20b': 1, 'c d': 2}
>>> resolve_pointer(obj, '') == obj
True
>>> resolve_pointer(obj, '/foo') == obj['foo']
True
>>> resolve_pointer(obj, '/foo/another prop') == obj['foo']['another prop']
True
>>> resolve_pointer(obj, '/foo/another prop/baz') == obj['foo']['another prop']['baz']
True
>>> resolve_pointer(obj, '/foo/anArray/0') == obj['foo']['anArray'][0]
True
>>> resolve_pointer(obj, '/some/path', None) == None
True
>>> resolve_pointer(obj, '/a b', None) == None
True
>>> resolve_pointer(obj, '/a%20b') == 1
True
>>> resolve_pointer(obj, '/c d') == 2
True
>>> resolve_pointer(obj, '/c%20d', None) == None
True
"""
pointer = JsonPointer(pointer)
return pointer.resolve(doc, default)
def pairwise(iterable):
""" Transforms a list to a list of tuples of adjacent items
s -> (s0,s1), (s1,s2), (s2, s3), ...
>>> list(pairwise([]))
[]
>>> list(pairwise([1]))
[]
>>> list(pairwise([1, 2, 3, 4]))
[(1, 2), (2, 3), (3, 4)]
"""
a, b = tee(iterable)
for _ in b:
break
return zip(a, b)
class JsonPointerException(Exception):
pass
class EndOfList:
"""Result of accessing element "-" of a list"""
def __init__(self, list_):
self.list_ = list_
def __repr__(self):
return '{cls}({lst})'.format(cls=self.__class__.__name__,
lst=repr(self.list_))
class JsonPointer:
"""A JSON Pointer that can reference parts of a JSON document"""
# Array indices must not contain:
# leading zeros, signs, spaces, decimals, etc
_RE_ARRAY_INDEX = re.compile('0|[1-9][0-9]*$')
_RE_INVALID_ESCAPE = re.compile('(~[^01]|~$)')
def __init__(self, pointer):
# validate escapes
invalid_escape = self._RE_INVALID_ESCAPE.search(pointer)
if invalid_escape:
raise JsonPointerException('Found invalid escape {}'.format(
invalid_escape.group()))
parts = pointer.split('/')
if parts.pop(0) != '':
raise JsonPointerException('Location must start with /')
parts = [unescape(part) for part in parts]
self.parts = parts
def to_last(self, doc):
"""Resolves ptr until the last step, returns (sub-doc, last-step)"""
if not self.parts:
return doc, None
for part in self.parts[:-1]:
doc = self.walk(doc, part)
return doc, JsonPointer.get_part(doc, self.parts[-1])
def resolve(self, doc, default=_nothing):
"""Resolves the pointer against doc and returns the referenced object"""
for part in self.parts:
try:
doc = self.walk(doc, part)
except JsonPointerException:
if default is _nothing:
raise
else:
return default
return doc
get = resolve
def set(self, doc, value, inplace=True):
"""Resolve the pointer against the doc and replace the target with value."""
if len(self.parts) == 0:
if inplace:
raise JsonPointerException('Cannot set root in place')
return value
if not inplace:
doc = copy.deepcopy(doc)
(parent, part) = self.to_last(doc)
if isinstance(parent, Sequence) and part == '-':
parent.append(value)
else:
parent[part] = value
return doc
@classmethod
def get_part(cls, doc, part):
"""Returns the next step in the correct type"""
if isinstance(doc, Mapping):
return part
elif isinstance(doc, Sequence):
if part == '-':
return part
if not JsonPointer._RE_ARRAY_INDEX.fullmatch(str(part)):
raise JsonPointerException("'%s' is not a valid sequence index" % part)
return int(part)
elif hasattr(doc, '__getitem__'):
# Allow indexing via ducktyping
# if the target has defined __getitem__
return part
else:
raise JsonPointerException("Document '%s' does not support indexing, "
"must be mapping/sequence or support __getitem__" % type(doc))
def get_parts(self):
"""Returns the list of the parts. For example, JsonPointer('/a/b').get_parts() == ['a', 'b']"""
return self.parts
def walk(self, doc, part):
""" Walks one step in doc and returns the referenced part """
part = JsonPointer.get_part(doc, part)
assert hasattr(doc, '__getitem__'), "invalid document type %s" % (type(doc),)
if isinstance(doc, Sequence):
if part == '-':
return EndOfList(doc)
try:
return doc[part]
except IndexError:
raise JsonPointerException("index '%s' is out of bounds" % (part,))
# Else the object is a mapping or supports __getitem__(so assume custom indexing)
try:
return doc[part]
except KeyError:
raise JsonPointerException("member '%s' not found in %s" % (part, doc))
def contains(self, ptr):
""" Returns True if self contains the given ptr """
return self.parts[:len(ptr.parts)] == ptr.parts
def __contains__(self, item):
""" Returns True if self contains the given ptr """
return self.contains(item)
def join(self, suffix):
""" Returns a new JsonPointer with the given suffix append to this ptr """
if isinstance(suffix, JsonPointer):
suffix_parts = suffix.parts
elif isinstance(suffix, str):
suffix_parts = JsonPointer(suffix).parts
else:
suffix_parts = suffix
try:
return JsonPointer.from_parts(chain(self.parts, suffix_parts))
except: # noqa E722
raise JsonPointerException("Invalid suffix")
def __truediv__(self, suffix):
return self.join(suffix)
@property
def path(self):
"""Returns the string representation of the pointer
>>> ptr = JsonPointer('/~0/0/~1').path == '/~0/0/~1'
"""
parts = [escape(part) for part in self.parts]
return ''.join('/' + part for part in parts)
def __eq__(self, other):
"""Compares a pointer to another object
Pointers can be compared by comparing their strings (or splitted
strings), because no two different parts can point to the same
structure in an object (eg no different number representations)
"""
if not isinstance(other, JsonPointer):
return False
return self.parts == other.parts
def __hash__(self):
return hash(tuple(self.parts))
def __str__(self):
return self.path
def __repr__(self):
return type(self).__name__ + "(" + repr(self.path) + ")"
@classmethod
def from_parts(cls, parts):
"""Constructs a JsonPointer from a list of (unescaped) paths
>>> JsonPointer.from_parts(['a', '~', '/', 0]).path == '/a/~0/~1/0'
True
"""
parts = [escape(str(part)) for part in parts]
ptr = cls(''.join('/' + part for part in parts))
return ptr
def escape(s):
return s.replace('~', '~0').replace('/', '~1')
def unescape(s):
return s.replace('~1', '/').replace('~0', '~')
You can’t perform that action at this time.