python-dataclasses

create dataclass with optional attribute Question: I’m trying create dataclass with optional attribute is_complete: from dataclasses import dataclass from typing import Optional @dataclass(frozen=True) class MyHistoricCandle: open: float high: float low: float close: float volume: int time: datetime is_complete: Optional[bool] But when i init MyHistoricCandle object without is_complete attribute: MyHistoricCandle(open=1, high=1, low=1, close=1, volume=1, time=datetime.now()) Getting …

Python typing for class that having methods from decorator Question: The dataclasses-json allows code such as: from dataclasses import dataclass from dataclasses_json import dataclass_json @dataclass_json @dataclass class Person: name: str lidatong = Person(‘lidatong’) # Encoding to JSON lidatong.to_json() # ‘{"name": "lidatong"}’ # Decoding from JSON Person.from_json(‘{"name": "lidatong"}’) # Person(name=’lidatong’) How could I use typing to …

function from_dict() failing for unknown reason in python Question: I converted below JSON using https://json2csharp.com/code-converters/json-to-python to a dataclass: { "bypassCd": [ "Duis sint ipsum in", "consequat" ] } It generaged below dataclass – for some reason, it is showing error at .from_dict() method and I’m unable to figure it out. Please advise from typing import …

A constructor for dataclasses with randomized attribute values Question: Hi could someone explain whats happening here: i want to instantiate objects with random values. @dataclass class Particle: pos = (random.randint(0, 800), random.randint(0, 800)) for _ in range(3): p = Particle() print(p.pos) prints: (123, 586) (123, 586) (123, 586) expected behaviour wold be three tuples with …

How can I restrict this dataclass serialization to only attributes on the base class? Question: Here’s some code: from dataclasses import dataclass from dataclasses_json import dataclass_json @dataclass_json @dataclass class Foo: f: str @dataclass_json @dataclass class Baz(Foo): b: str def full(self): return self.to_dict() # as expected, returns {"f":"f", "b":"b"} def partial(self): return Foo.to_dict(self) # also returns …

How to update a property for all dataclass objects in a list? Question: I have a list of objects of the following type: @dataclass class Feature: name: str active: bool and my list is: features = [Feature("name1",False), Feature("name2",False), Feature("name3",True)] I want to get back a list with all the features but switch their active property …

Iterating through a list with dataclasses, and checking if an element matches the inputted int? Question: I"m having a bit of trouble with my code. I’m trying to get the IDs from the list and compare it to an int input. If the int is the same as the ID, it’ll print("Yes"). If it doesn’t …

What other types of classes are there in Python? Question: I just found out about dataclasses and was reading some tutorials on how to use them. One tutorial described data classes as: A data class is a class typically containing mainly data, although there aren’t really any restrictions. What other types of classes are there …

Python dataclass: Forcing a dictionary field to be a deep copy Question: I am working with a dataclass that contains a dict. I want the dict to be a deepcopy, without having to rely on a post_init call, which would basically void to interest of a dataclass What would be a nice solution ? from …

How to handle typing of member variable that is initialized during __post_init__() of dataclass Question: The variable below is initialized as none, but during __post_init__ it is replaced with an instance of outlook client. @dataclass class Config: """Outlook configuration""" mailbox: str inbox: str mailbox_obj: Union["Mailbox", None] = None However, static type analysis correctly informs that …