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| -rw-r--r-- | .gitignore | 2 | ||||
| -rw-r--r-- | AUTHORS | 1 | ||||
| -rw-r--r-- | COPYING | 26 | ||||
| -rw-r--r-- | README | 11 | ||||
| -rw-r--r-- | jsonpatch.py | 221 | ||||
| -rw-r--r-- | setup.py | 33 |
6 files changed, 294 insertions, 0 deletions
diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..27ffc2f --- /dev/null +++ b/.gitignore @@ -0,0 +1,2 @@ +*.pyc +build @@ -0,0 +1 @@ +Stefan Kögl <stefan@skoegl.net> @@ -0,0 +1,26 @@ +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. + @@ -0,0 +1,11 @@ + +python-json-patch: Applying JSON Patches +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Library to apply JSON Patches according to +http://tools.ietf.org/html/draft-pbryan-json-patch-01 + +See Sourcecode for Examples + +Website: https://github.com/stefankoegl/python-json-patch +Repository: https://github.com/stefankoegl/python-json-patch.git diff --git a/jsonpatch.py b/jsonpatch.py new file mode 100644 index 0000000..3136567 --- /dev/null +++ b/jsonpatch.py @@ -0,0 +1,221 @@ +# -*- coding: utf-8 -*- +# +# python-json-patch - An implementation of the JSON Patch format +# https://github.com/stefankoegl/python-json-patch +# +# 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. +# + +"""Apply JSON-Patches according to http://tools.ietf.org/html/draft-pbryan-json-patch-01""" + +# Will be parsed by setup.py to determine package metadata +__author__ = 'Stefan Kögl <stefan@skoegl.net>' +__version__ = '0.1' +__website__ = 'https://github.com/stefankoegl/python-json-patch' +__license__ = 'Modified BSD License' + + +import copy +import json + + +class JsonPatchException(Exception): + pass + + +class JsonPatch(object): + """ A JSON Patch is a list of Patch Operations """ + + def __init__(self, patch): + self.patch = patch + + self.OPERATIONS = { + 'remove': RemoveOperation, + 'add': AddOperation, + 'replace': ReplaceOperation, + } + + + @classmethod + def from_string(cls, patch_str): + patch = json.loads(patch_str) + return cls(patch) + + + def apply(self, obj): + """ Applies the patch to a copy of the given object """ + + obj = copy.deepcopy(obj) + + for operation in self.patch: + op = self._get_operation(operation) + op.apply(obj) + + return obj + + + def _get_operation(self, operation): + for action, op_cls in self.OPERATIONS.items(): + if action in operation: + location = operation[action] + op = op_cls(location, operation) + return op + + raise JsonPatchException("invalid operation '%s'" % operation) + + + +class PatchOperation(object): + """ A single operation inside a JSON Patch """ + + def __init__(self, location, operation): + self.location = location + self.operation = operation + + + def locate(self, obj, location, last_must_exist=True): + """ Walks through the object according to location + + Returns the last step as (sub-object, last location-step) """ + + parts = location.split('/') + if parts.pop(0) != '': + raise JsonPatchException('location must starts with /') + + for part in parts[:-1]: + obj, loc_part = self._step(obj, part) + + _, last_loc = self._step(obj, parts[-1], must_exist=last_must_exist) + return obj, last_loc + + + def _step(self, obj, loc_part, must_exist=True): + """ Goes one step in a locate() call """ + + # Its not clear if a location "1" should be considered as 1 or "1" + # We prefer the integer-variant if possible + part_variants = self._try_parse(loc_part) + [loc_part] + + for variant in part_variants: + try: + return obj[variant], variant + except: + continue + + if must_exist: + raise JsonPatchException('key %s not found' % loc_part) + else: + return obj, part_variants[0] + + + @staticmethod + def _try_parse(val, cls=int): + try: + return [cls(val)] + except: + return [] + + +class RemoveOperation(PatchOperation): + """ Removes an object property or an array element + + >>> obj = { 'baz': 'qux', 'foo': 'bar' } + >>> patch = JsonPatch( [ { 'remove': '/baz' } ] ) + >>> patch.apply(obj) + {'foo': 'bar'} + + >>> obj = { 'foo': [ 'bar', 'qux', 'baz' ] } + >>> patch = JsonPatch( [ { "remove": "/foo/1" } ] ) + >>> patch.apply(obj) + {'foo': ['bar', 'baz']} + """ + + def apply(self, obj): + subobj, part = self.locate(obj, self.location) + del subobj[part] + + +class AddOperation(PatchOperation): + """ Adds an object property or an array element + + >>> obj = { "foo": "bar" } + >>> patch = JsonPatch([ { "add": "/baz", "value": "qux" } ]) + >>> patch.apply(obj) + {'foo': 'bar', 'baz': 'qux'} + + >>> obj = { "foo": [ "bar", "baz" ] } + >>> patch = JsonPatch([ { "add": "/foo/1", "value": "qux" } ]) + >>> patch.apply(obj) + {'foo': ['bar', 'qux', 'baz']} + """ + + def apply(self, obj): + value = self.operation["value"] + subobj, part = self.locate(obj, self.location, last_must_exist=False) + + if isinstance(subobj, list): + if part > len(subobj) or part < 0: + raise JsonPatchException("can't insert outside of list") + + subobj.insert(part, value) + + elif isinstance(subobj, dict): + if part in subobj: + raise JsonPatchException("object '%s' already exists" % part) + + subobj[part] = value + + else: + raise JsonPatchException("can't add to type '%s'" % subobj.__class__.__name__) + + +class ReplaceOperation(PatchOperation): + """ Replaces a value + + >>> obj = { "baz": "qux", "foo": "bar" } + >>> patch = JsonPatch([ { "replace": "/baz", "value": "boo" } ]) + >>> patch.apply(obj) + {'foo': 'bar', 'baz': 'boo'} + """ + + def apply(self, obj): + location = self. operation["replace"] + value = self.operation["value"] + subobj, part = self.locate(obj, self.location) + + if isinstance(subobj, list): + if part > len(subobj) or part < 0: + raise JsonPatchException("can't replace outside of list") + + elif isinstance(subobj, dict): + if not part in subobj: + raise JsonPatchException("can't replace non-existant object '%s'" % part) + + else: + raise JsonPatchException("can't replace in type '%s'" % subobj.__class__.__name__) + + subobj[part] = value diff --git a/setup.py b/setup.py new file mode 100644 index 0000000..c9a3900 --- /dev/null +++ b/setup.py @@ -0,0 +1,33 @@ +#!/usr/bin/env python + +from distutils.core import setup +import re + +src = open('jsonpatch.py').read() +metadata = dict(re.findall("__([a-z]+)__ = '([^']+)'", src)) +docstrings = re.findall('"""(.*)"""', src) + +PACKAGE = 'jsonpatch' + +MODULES = ( + 'jsonpatch', +) + +AUTHOR_EMAIL = metadata['author'] +VERSION = metadata['version'] +WEBSITE = metadata['website'] +LICENSE = metadata['license'] +DESCRIPTION = docstrings[0] + +# Extract name and e-mail ("Firstname Lastname <mail@example.org>") +AUTHOR, EMAIL = re.match(r'(.*) <(.*)>', AUTHOR_EMAIL).groups() + +setup(name=PACKAGE, + version=VERSION, + description=DESCRIPTION, + author=AUTHOR, + author_email=EMAIL, + license=LICENSE, + url=WEBSITE, + py_modules=MODULES, +) |