dataclass-factory 0.5

An utility class for creating instances of dataclasses

dataclass_factory

Why

You can convert dataclass to dict using asdict method, but cannot convert back. This module provides parse method for such task.

What's supported

• dataclass from dict
• Enum from value
• List, Set, FrozenSet, Dict with specified type
• Tuple with specified types or ellipsis
• Optional with specified type
• Union parsed in order of given types
• Any returned as is

Usage

Install:

pip install dataclass_factory 

Code:

@dataclass
class Book:
    title: str
    author: str = "Unknown author"


data = {
    "title": "Fahrenheit 451"
}

obj = dataclass_factory.parse(data, Book)  # Same as Book(title="Fahrenheit 451")

More complex example

@dataclass 
class Disk:
    title: str
    artist: str
    
    
@dataclass
class Store:
    items: List[Union[Disk, Book]]
     


data = {
    "items": [
        {"title": "Fahrenheit 451", "author": "Bradbury"},
        {"title": "Dark Side of the Moon", "artist": "Pink Floyd"}
    ]
}

expected = Store(
    items=[
        Book(title='Fahrenheit 451', author='Bradbury'),
        Disk(title='Dark Side of the Moon', artist='Pink Floyd')
    ]
)

assert expected == dataclass_factory.parse(data, Store)