Pykson: A JSON Serializer/Deserializer for Python

Pykson is a JSON serializer/deserializer in python.

Tested with:

Python 3.6+

Use the following command to install using pip:

pip install pykson

Usage example

Create Object Models

First, create your object model which extends JsonObject

from pykson import JsonObject, IntegerField, StringField, ObjectListField


class Course(JsonObject):
    name = StringField()
    teacher = StringField()


class Score(JsonObject):
    score = IntegerField()
    course = Course()


class Student(JsonObject):

    first_name = StringField()
    last_name = StringField()
    age = IntegerField()
    scores = ObjectListField(Score)

Deserialize json strings

Use Pykson class to deserialize json string to JsonObjects

from pykson import Pykson

json_text = '{"first_name":"John", "last_name":"Smith", "age": 25, "scores": [ {"course": {"name": "Algebra", "teacher" :"Mr. Schmidt"}, "score": 100}, {"course": {"name": "Statistics", "teacher": "Mrs. Lee"}, "score": 90} ]}'
student = Pykson.from_json(json_text, Student)

Serialize objects

Use Pykson class to serialize JsonObjects to string

Pykson.to_json(student)

Fields

There are different types of predefined fields: IntegerField, FloatField, BooleanField, StringField, ListField, ObjectField, ObjectListField, DateField, TimeField, DateTimeField, TimestampSecondsField and TimestampMillisecondsField.

There are four other types of fields which help with storing fields with specific integer or string values. To create a field with multiple choice integer values, use MultipleChoiceIntegerField or EnumIntegerField classes. To create a field with multiple choice string values, use MultipleChoiceStringField or EnumStringField classes.

Example for MultipleChoiceStringField:

from pykson import MultipleChoiceStringField

class WeatherInfo(JsonObject):

  condition = MultipleChoiceStringField(options=['sunny','cloudy','rainy'], null=False)

Example for EnumStringField:

from enum import Enum
from pykson import EnumStringField

class WeatherCondition(Enum):
  SUNNY = 'sunny'
  CLOUDY = 'cloudy'
  RAINY = 'rainy'


class WeatherInfo(JsonObject):
  condition = EnumStringField(enum=WeatherCondition, null=False)

Advanced usage

Serialized names

It is possible to use change name of fields during serialization/deserialization. For this purpose, use serialized_name input in the fields

from pykson import Pykson, JsonObject, IntegerField, StringField, ObjectField
class Score(JsonObject):
    score = IntegerField(serialized_name="s")
    course = StringField(serialized_name="c")


class Student(JsonObject):

    first_name = StringField(serialized_name="fn")
    last_name = StringField(serialized_name="ln")
    age = IntegerField(serialized_name="a")
    score = ObjectField(Score, serialized_name="s")


json_text = '{"fn":"John", "ln":"Smith", "a": 25, "s": {"s": 100, "c":"Algebra"}}'
student = Pykson.from_json(json_text, Student)

Work with dates and datetimes

Pykson currenty has five fields for handling dates and datetimes. Three of them, DateField, TimeField and DateTimeField, use date/time formats to serialize/deserialize values. The other ones, TimestampSecondsField and TimestampMillisecondsField use integer values to serialize/deserialize datetimes.

ttutko/pykson