As of redis-py 4.0.0 this library is deprecated. It's features have been merged into redis-py. Please either install it from pypy or the repo.
rejson-py is a package that allows storing, updating and querying objects as JSON documents in a Redis database that is extended with the ReJSON module. The package extends redis-py's interface with ReJSON's API, and performs on-the-fly serialization/deserialization of objects to/from JSON.
$ pip install rejson- Create a virtualenv to manage your python dependencies, and ensure it's active.
virtualenv -v venv - Install pypoetry to manage your dependencies.
pip install --user poetry - Install dependencies.
poetry install
tox runs all tests as its default target. Running tox by itself will run unit tests. Ensure you have a running redis, with the module loaded.
fromrejsonimportClient, Pathrj=Client(host='localhost', port=6379, decode_responses=True)
# Set the key `obj` to some objectobj= {
'answer': 42,
'arr': [None, True, 3.14],
'truth': {
'coord': 'out there'
}
}
rj.jsonset('obj', Path.rootPath(), obj)
# Get somethingprint'Is there anybody... {}?'.format(
rj.jsonget('obj', Path('.truth.coord'))
)
# Delete something (or perhaps nothing), append something and pop itrj.jsondel('obj', Path('.arr[0]'))
rj.jsonarrappend('obj', Path('.arr'), 'something')
print'{} popped!'.format(rj.jsonarrpop('obj', Path('.arr')))
# Update something elserj.jsonset('obj', Path('.answer'), 2.17)
# And use just like the regular redis-py clientjp=rj.pipeline()
jp.set('foo', 'bar')
jp.jsonset('baz', Path.rootPath(), 'qaz')
jp.execute()
# If you use non-ascii character in your JSON data, you can add the no_escape flag to JSON.GET commandobj_non_ascii= {
'non_ascii_string': 'hyvää'
}
rj.jsonset('non-ascii', Path.rootPath(), obj_non_ascii)
print'{} is a non-ascii string'.format(rj.jsonget('non-ascii', Path('.non_ascii_string'), no_escape=True))rejson-py uses Python's json. The client can be set to use custom encoders/decoders at creation, or by calling explicitly the setEncoder() and setDecoder() methods, respectively.
The following shows how to use this for a custom class that's stored as a JSON string for example:
fromjsonimportJSONEncoder, JSONDecoderfromrejsonimportClientclassCustomClass(object):
"Some non-JSON-serializable"def__init__(self, s=None):
ifsisnotNone:
# deserialize the instance from the serializationifs.startswith('CustomClass:'):
...
else:
raiseException('unknown format')
else:
# initialize the instance
...
def__str__(self):
_str='CustomClass:'# append the instance's state to the serialization
...
return_str
...
classCustomEncoder(JSONEncoder):
"A custom encoder for the custom class"defdefault(self, obj):
ifisinstance(obj, CustomClass):
returnstr(obj)
returnjson.JSONEncoder.encode(self, obj)
classTestDecoder(JSONDecoder):
"A custom decoder for the custom class"defdecode(self, obj):
d=json.JSONDecoder.decode(self, obj)
ifisinstance(d, basestring) andd.startswith('CustomClass:'):
returnCustomClass(d)
returnd# Create a new instance of CustomClassobj=CustomClass()
# Create a new client with the custom encoder and decoderrj=Client(encoder=CustomEncoder(), decoder=CustomDecoder())
# Store the objectrj.jsonset('custom', Path.rootPath(), obj))
# Retrieve itobj=rj.jsonget('custom', Path.rootPath())As rejson-py exposes the same methods as redis-py, it can be used as a drop-in replacement. On top of Redis' core commands, the client also adds ReJSON's vocabulary and a couple of helper methods. These are documented in the API.md file, which can be generated by running:
$ python gendoc rejson > API.mdFor complete documentation about ReJSON's commands, refer to ReJSON's website.