JSON Merge Patch Library

This library provides functions to merge json in accordance with https://tools.ietf.org/html/rfc7386

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Install using pip:

pip install json-merge-patch

Or you can clone the repository and paste:

python setup.py install

or for development use:

python setup.py develop

This requires setuptools to be installed. It has no dependencies outside the stadard library so no pip requirements files are needed.

To test run:

python -m unittest discover

Usage as a library

The library does not deal with json loading and dumping that is up to the user.

There are two functions:

merge: Takes a list of input dictionaries and merges them in turn.

create_patch: Takes 2 dictionaries the original and the target and gives you the minimal patch needed to go from the original to the target. So if merge(a, b) == c then create_patch(a, c) == b.

Merge example

import json_merge_patch

input1 = {"a": 1}
input2 = {"a": 2, "b": 3}

result = json_merge_patch.merge(input1, input2)

print(result)
# {'a': 2, 'b': 3}

Create Patch example

input1 = {"a": 1}
results = {'a': 2, 'b': 3}

patch = json_merge_patch.create_patch(input1, result)
print(patch)
# {'a': 2, 'b': 3}

Merge example preserving order. Inputs need to be OrderedDicts. Will error otherwise. Argument "position" can either be 'first', 'last'.

import json_merge_patch

input1 = OrderedDict([("a", 1)])
input2 = OrderedDict([("a", 1), ("b", 3)])

result = json_merge_patch.merge(input1, input2, position="first")
print(result)
# {'b': 3, 'a': 2}

Usage as a command line tool

Has two functions

json-merge-patch merge input1.json input2.json 

json-merge-patch create-patch original.json target.json 

By default results are printed to stdout. If you use the -o flag they can be saved to a file.

json-merge-patch merge input1.json input2.json -o output.json

json-merge-patch create-patch original.json target.json -o patch.json

More can be found at:

json-merge-patch merge --help

json-merge-patch create-patch --help