Tutorial¶
Please refer to RFC 6901 for the exact
pointer syntax. jsonpointer
has two interfaces. The resolve_pointer
method is basically a deep get
.
>>> from jsonpointer import resolve_pointer
>>> obj = {"foo": {"anArray": [ {"prop": 44}], "another prop": {"baz": "A string" }}}
>>> 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
The set_pointer
method allows modifying a portion of an object using
JSON pointer notation:
>>> from jsonpointer import set_pointer
>>> 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}]}}
>>> obj
{'foo': {'another prop': {'baz': 'A string'}, 'anArray': [{'prop': 55}]}}
By default set_pointer
modifies the original object. Pass inplace=False
to create a copy and modify the copy instead:
>>> from jsonpointer import set_pointer
>>> obj = {"foo": {"anArray": [ {"prop": 44}], "another prop": {"baz": "A string" }}}
>>> set_pointer(obj, '/foo/anArray/0/prop', 55, inplace=False)
{'foo': {'another prop': {'baz': 'A string'}, 'anArray': [{'prop': 55}]}}
>>> obj
{'foo': {'another prop': {'baz': 'A string'}, 'anArray': [{'prop': 44}]}}
The JsonPointer
class wraps a (string) path and can be used to access the
same path on several objects.
>>> import jsonpointer
>>> pointer = jsonpointer.JsonPointer('/foo/1')
>>> obj1 = {'foo': ['a', 'b', 'c']}
>>> pointer.resolve(obj1)
'b'
>>> obj2 = {'foo': {'0': 1, '1': 10, '2': 100}}
>>> pointer.resolve(obj2)
10