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pythonpython-dataclasses

how to convert a dict to a dataclass (reverse of asdict)?

the dataclasses module lets users make a dict from a dataclass reall conveniently, like this:

from dataclasses import dataclass, asdict

@dataclass
class MyDataClass:
    ''' description of the dataclass '''
    a: int
    b: int
    
# create instance
c = MyDataClass(100, 200)
print(c)

# turn into a dict
d = asdict(c)
print(d)

But i am trying to do the reverse process: dict -> dataclass.

The best that i can do is unpack a dict back into the predefined dataclass.

# is there a way to convert this dict to a dataclass ?
my_dict = {'a': 100, 'b': 200}
e = MyDataClass(**my_dict)
print(e)

How can i achieve this without having to pre-define the dataclass (if it is possible) ?

Solution

  • You can use make_dataclass:

    from dataclasses import make_dataclass

my_dict = {"a": 100, "b": 200}
make_dataclass(
    "MyDynamicallyCreatedDataclass", ((k, type(v)) for k, v in my_dict.items())
)(**my_dict)