simple serializer based on annotations


Keywords
json, serializer, annotation, validation
License
GPL-3.0
Install
pip install ajson==0.12.0

Documentation

AJson (Annotations Json Serializer)

AJson is a serializer based on annotations that gives a lot of flexibility and configuration for you serialization process.

Build Status codecov

Install: (python3.6 or greater)

pip install ajson

Motivation:

There are amazing serialization libraries like jsonpickle, and even more when the serialized object is meant to be used in python too. But there are no libraries that let you filter the fields to serialize or modify the names of the attributes, which are features super useful, mainly for http APIs

This library allows you to have those features in a simple and intuitive way.

Serialize Examples

Simple Serialization With "Groups"

If you want to filter some sensible data in some scenarios, you can define groups per each attribute to control what is serialize and what is not

from ajson import AJson, ASerializer

@AJson()
class Restaurant:
    location:str   # @aj(groups=["public","admin"])
    tables: int  # @aj(groups=["public","admin"])
    owner: str  # @aj(groups=["admin"])
    def __init__(self, location, tables, owner):
        self.location = location
        self.tables = tables
        self.owner = owner

serializer = ASerializer()
restaurant = Restaurant("Manhattan", 30, "John Smith")
print(serializer.serialize(restaurant, groups=["public"])) 
# {"location": "Manhattan", "tables": 30}
print(serializer.serialize(restaurant, groups=["admin"])) 
#  {"location": "Manhattan", "tables": 30, "owner": "John Smith"}
Rename Attributes With "Name"
from ajson import AJson
from ajson.aserializer import ASerializer

@AJson()
class Customer:
    name: str  # @aj(name=firstName)
    primary_email: str  # @aj(name=email)
    last_name: str  # @aj(name=lastName)
    def __init__(self):
        self.name = "John"
        self.last_name = "Smith"
        self.primary_email = "john.smith@something.com"

serializer = ASerializer()
customer = Customer()
print(serializer.serialize(customer))
# {"firstName": "John", "lastName": "Smith", "email": "john.smith@something.com"}
Nested Objects With Groups And Names
from typing import List
from ajson import AJson, ASerializer


@AJson()
class Customer:
    name: str  # @aj(name=firstName, groups=["public"])
    primary_email: str
    '''
    You can also add the annotation in a multiline docstr
    @aj(
        name=email,
        groups=["public"]
    )
    '''

    def __init__(self, name, primary_email):
        self.name = name
        self.primary_email = primary_email

@AJson()
class Restaurant:
    location: str  # @aj(groups=["public","admin"])
    owner: str  # @aj(groups=["admin"])
    customer_list: List[Customer]  # @aj(groups=["with_customers"] name=customers)

    def __init__(self):
        self.location = None
        self.owner = "John Smith"
        self.customer_list = [
            Customer("Dani", "dani@something.com"),
            Customer("Mike", "maki@something.com")
        ]

restaurant = Restaurant()
print(ASerializer().serialize(restaurant, groups=["public"]))
# '{"location": null}'

# if you want to get the dictionary instead of a string, you can call `to_dict` instead of `serialize`
print(ASerializer().to_dict(restaurant, groups=["public", "with_customers"]))
'''
{
    "location": None,
    "customers": [
        {"firstName": "Dani", "email": "dani@something.com"},
        {"firstName": "Mike", "email": "maki@something.com"}
    ]
}
'''

Unserialize Examples

UnSerialization With Custom Names
from ajson import AJson, ASerializer

@AJson()
class Customer:
    name: str  # @aj(name=firstName)
    primary_email: str  # @aj(name=email)
    last_name: str  # @aj(name=lastName)

serializer = ASerializer()
serialize_str = '{"firstName": "John", "lastName": "Smith", "email": "john.smith@something.com"}'
customer = serializer.unserialize(serialize_str, Customer)
print(customer.name)  # "John"
print(customer.last_name)  # "Smith"
print(customer.primary_email)  # "john.smith@something.com"
Nested Objects
from typing import List, Optional
from ajson import AJson, ASerializer


@AJson()
class Customer:
    def __init__(self):
        # we can also create the @aj annotation in the attribute's definition
        self.name = None  # @aj(name=firstName)
        self.primary_email = None  # @aj(name=email)

@AJson()
class Restaurant:
    customer_list: List[Customer]  # if we want to have nested objects, we need to define the types hints
    '''
        @aj(name=customers)
        we can create the @aj annotation in the attribute's definition
    '''
    owner: str = "John Smith"
    location: Optional[str] = None
        

restaurant_str = '''
{
    "location": "Spain",
    "customers": [
        {"firstName": "Dani", "email": "dani@something.com"},
        {"firstName": "Mike", "email": "maki@something.com"}
    ]
}
'''

serializer = ASerializer()
restaurant = serializer.unserialize(restaurant_str, Restaurant)
print(restaurant.owner)  # "John Smith"
print(restaurant.customer_list[0].name)  # "Dani"
Known Limitations
  1. Unserialize a Dict with types (Dict[str:MyObject]) is not supported, it will just unserialize it as a dict.

  2. Unserialize a Dict with key different than a string (Dict[int:str])

  3. Properties serialization is not supported yet.

Documentation

Documentation and additional information is available here

Contributing

Any contribution, feature request, or bug report is always welcome.

Please, feel free to create any issues or PRs.