Installation#

Available from PyPI:

pip install serious

Models In Short#

Models are the central part of the serious API:

from serious import JsonModel

model = JsonModel(Stock)

model.load('{"name": "AAPL", "price": "139.38"}')

You encode, decode and validate the dataclasses via model methods.

Model constructor allows to change the specifics of working with particular dataclass, e.g. JsonModel(Job, allow_missing=True) will set None to fields marked Optional in Job dataclass when they are missing from loaded JSON.

There are two types of Model as of now:

1. JsonModel for JSON formatted strings.
2. DictModel for Python dict objects.

For more refer to models docs.

Simple Serialization#

Having a dataclass:

from dataclasses import dataclass

@dataclass
class Person:
    name: str

Create an instance of JsonModel:

from serious.json import JsonModel

model = JsonModel(Person)

And use its dump/load methods:

person = Person('Albert Einstein')

model.dump(person) # {"name": "Albert Einstein"}

More on serialization.

Basic Validation#

To validate instance of a dataclass upon load — add a __validate__ method to it:

from dataclasses import dataclass
from typing import List
from serious import DictModel, ValidationError

@dataclass
class Order:
    lines: List[str]

    def __validate__(self):
        if len(self.lines) == 0:
            raise ValidationError('Order cannot be empty')

model = DictModel(Order)

Now passing an invalid object for decoding to this model will result in ValidationError:

try:
    model.load({'lines': []})
except ValidationError as e:
    print(str(e)) # Order cannot be empty

More on validation.