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==========
Quickstart
==========
Here are the supported features that Dataclass Wizard currently provides:
- *JSON (de)serialization*: marshal dataclasses to/from JSON and Python
``dict`` objects.
- *Field properties*: support for using properties with default
values in dataclass instances.
The below is an quick demo of both of these features - how to marshal dataclasses to/from JSON and Python ``dict`` objects,
and declare and use field properties with default values.
.. code:: python3
from dataclasses import dataclass, field
from datetime import datetime
from typing import Optional
from dataclass_wizard import JSONSerializable, property_wizard
@dataclass
class MyClass(JSONSerializable, metaclass=property_wizard):
my_str: Optional[str]
list_of_int: list[int] = field(default_factory=list)
# You can also define this as `my_dt`, however only the annotation
# will carry over in that case, since the value is re-declared by
# the property below. See also the 'Using Field Properties' section
# in the docs for a more elegant approach.
_my_dt: datetime = datetime(2000, 1, 1)
@property
def my_dt(self):
"""
A sample `getter` which returns the datetime with year set as 2010
"""
if self._my_dt is not None:
return self._my_dt.replace(year=2010)
return self._my_dt
@my_dt.setter
def my_dt(self, new_dt: datetime):
"""
A sample `setter` which sets the inverse (roughly) of the `month` and `day`
"""
self._my_dt = new_dt.replace(
month=13 - new_dt.month,
day=31 - new_dt.day)
string = '''{"myStr": 42, "listOFInt": [1, "2", 3]}'''
# Uses the default value for `my_dt`, with year=2000, month=1, day=1
c = MyClass.from_json(string)
print(repr(c))
# prints:
# MyClass(my_str='42', list_of_int=[1, 2, 3], my_dt=datetime.datetime(2010, 12, 30, 0, 0))
my_dict = {'My_Str': 'string', 'myDT': '2021-01-20T15:55:30Z'}
c = MyClass.from_dict(my_dict)
print(repr(c))
# prints:
# MyClass(my_str='string', list_of_int=[], my_dt=datetime.datetime(2010, 12, 11, 15, 55, 30, tzinfo=datetime.timezone.utc))
print(c.to_json())
# prints:
# {"myStr": "string", "listOfInt": [], "myDt": "2010-12-11T15:55:30Z"}
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