diff options
Diffstat (limited to 'jsonpointer.py')
| -rw-r--r-- | jsonpointer.py | 54 |
1 files changed, 49 insertions, 5 deletions
diff --git a/jsonpointer.py b/jsonpointer.py index fe7914a..648a377 100644 --- a/jsonpointer.py +++ b/jsonpointer.py @@ -50,6 +50,7 @@ except ImportError: # Python 3 from itertools import tee import re +import copy # array indices must not contain leading zeros, signs, spaces, decimals, etc @@ -104,6 +105,28 @@ def resolve_pointer(doc, pointer, default=_nothing): pointer = JsonPointer(pointer) return pointer.resolve(doc, default) +def set_pointer(doc, pointer, value, inplace=True): + """ + Resolves 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%20another%20prop', 'added prop') == \ + {'foo': {'another prop': {'baz': 'A string'}, 'yet another prop': 'added prop', 'anArray': [{'prop': 55}]}} + True + + """ + + pointer = JsonPointer(pointer) + return pointer.set(doc, value, inplace) + class JsonPointer(object): """ A JSON Pointer that can reference parts of an JSON document """ @@ -149,6 +172,21 @@ class JsonPointer(object): 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) + + parent[part] = value + return doc def get_part(self, doc, part): """ Returns the next step in the correct type """ @@ -166,8 +204,13 @@ class JsonPointer(object): return int(part) + elif hasattr(doc, '__getitem__'): + # Allow indexing via ducktyping if the target has defined __getitem__ + return part + else: - raise JsonPointerException("Unknown document type '%s'" % (doc.__class__,)) + raise JsonPointerException("Document '%s' does not support indexing, " + "must be dict/list or support __getitem__" % type(doc)) def walk(self, doc, part): @@ -175,9 +218,7 @@ class JsonPointer(object): part = self.get_part(doc, part) - # type is already checked in get_part, so we assert here - # for consistency - assert type(doc) in (dict, list), "invalid document type %s" (type(doc),) + assert (type(doc) in (dict, list) or hasattr(doc, '__getitem__')), "invalid document type %s" (type(doc)) if isinstance(doc, dict): try: @@ -197,9 +238,12 @@ class JsonPointer(object): except IndexError: raise JsonPointerException("index '%s' is out of bounds" % (part, )) + else: + # Object supports __getitem__, assume custom indexing + return doc[part] def contains(self, ptr): - """" Returns True if self contains the given ptr """ + """ Returns True if self contains the given ptr """ return len(self.parts) > len(ptr.parts) and \ self.parts[:len(ptr.parts)] == ptr.parts |