I’ve been working on a class that utilises abstract methods. However, I’m getting a mypy error for overwriting the function declaration in each child class. Could someone please explain to me how I can achieve the same effects, whilst also obeying mypy’s desires. from abc import ABC, abstractmethod from typing import Any class Base(ABC): def ..
I’m trying to define a class that takes another class as an attribute _model and will instantiate objects of that class. from abc import ABC from typing import Generic, TypeVar, Any, ClassVar, Type Item = TypeVar("Item", bound=Any) class SomeClass(Generic[Item], ABC): _model: ClassVar[Type[Item]] def _compose_item(self, **attrs: Any) -> Item: return self._model(**attrs) I think it should be ..
Is it possible to force an abstract method to be defined if and only if a condition is met? import abc class MyAbstract(abc.ABC): def __init__(self, need_foo: bool = True): self.__set_foo_method_only_if_needed(need_foo) # Set “foo“ as an abstract method @abc.abstractmethod def bar(self): pass def __set_foo_method_only_if_needed(self, need_foo): if need_foo: # Do the magic here to define “foo“ as ..
I’m using Pydantic to define hierarchical data in which there are models with identical attributes. However, when I save and load these models, Pydantic can no longer distinguish which model was used and picks the first one in the field type annotation. I understand that this is expected behavior based on the documentation. However, the ..
I have a need to add listeners to models who inherit from a mixin, and I want the mixin to have abstract methods that the overriding classes must implement to follow the mixin spec, like so: from abc import ABC, abstractmethod from app import db from sqlalchemy.orm import declarative_mixin @declarative_mixin class FooMixin(ABC): @abstractmethod def must_implement(self): ..
I have an abstract baseclass which uses a value whose implementation in different concrete classes can be either an attribute or a property: class Base(ABC): n: int def foo(self): … a = … + self.n @abstractmethod def bar(self): … class X(Base): def __init__(self, n: int): self.n = n def bar(self): … class Y(Base): @property def ..
I have a question on multi level inheritance. I am trying to write classes of the form: from abc import ABC, abstractmethod import numpy as np ### Parent class class A(ABC): @abstractmethod def eval(self, x: np.ndarray) -> np.ndarray: pass @abstractmethod def func(self, x: np.ndarray) -> None: pass ### 1. Inheritance class B1(A): def eval(self, x: ..
I was reading the book Fluent Python by Luciano Ramalho and I encountered the following line: Note that the built-in concrete sequence types do not actually subclass the Sequence and MutableSequence abstract base classes (ABCs) depicted So I looked into ABCs from Python docs and I am having problems understanding their purpose. For example, isinstance(, ..
I have a complex class structure such has this one below: from abc import ABC, abstractmethod from abc import ABC, abstractmethod # Abstract Foo Space class Foo(ABC): def __init__(self, value): self.value = value @abstractmethod def foo_something(self): pass class ChildFoo(Foo): def __init__(self, value, extended_foo): Foo.__init__(self, value=value) self.extended_foo = extended_foo def foo_something(self): print(self.extended_foo) # Abstract Bar Space, ..
I have the following code segment, which is shown as follows along with its output from abc import ABCMeta, abstractmethod class AbstractClass(object, metaclass=ABCMeta): @abstractmethod def __init__(self, n): self.n = n print(‘the salary information’) class Employee(AbstractClass): def __init__(self, salary, name): self.salary = salary self.name = name super(AbstractClass,self).__init__() emp1 = Employee(1000000, "Tom") print(emp1.salary) print(emp1.name) I would like ..