Category : class-method

Since python 3.9, it is supported to stack the @property and @classmethod decorators. However, I struggle to create a class-property that shows up in help under the Readonly properties section. The solutions presented in [1],[2],[3],[4], didn’t solve my problem. Consider: from abc import ABC, ABCMeta, abstractmethod class MyMetaClass(ABCMeta): @property def expensive_metaclass_property(cls): """This may take a ..

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I think I am missing something basic in sqlalchemy function definition. I defined two classes (Parent and Child) with one-to-many relationship. And I want (additionally to the aggregated method) that there will be a method in Parent class that returns all distinct Child.value as a list. The code that I have: ”’ class Parent(Base): __tablename__ ..

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There are three methods in python’s oop concept–instance method ,class method ,static method. class MyClass: def instancemethod(self): return ‘instance method called’ @classmethod def classmethod(cls): return ‘class method called’ @staticmethod def staticmethod(): return ‘static method called’ It is obvious to know all three methods.Now i create a new method in a class: class Test(): def ppr(): ..

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I would like to initialize an instance and let both args and kwargs become class variables. class Example(): def __init__( self, a: str, b: bool, c: int, d="str", e=True, f=123, ): class_member = dict(locals()) del class_member["self"] self.set_property(class_member) @classmethod def set_property(cls, kwargs): for key, value in kwargs.items(): setattr(cls, key, value) a = Example("test", True, 1, d="test", ..

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For example: class A: factor = 2 def salary(self): base_sal = 10000 sal = base_sal*factor print("Your Salary:",sal) @classmethod def inc_factor(cls): cls.factor += 0.1 def increase_factor(): A.factor += 0.1 Why can’t we just use A.increase_factor() rather than using the @classmethod as it will only function inside the A class and why is worth passing class argument ..

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Consider the following metaclass/class definitions: class Meta(type): """A python metaclass.""" def greet_user(cls): """Print a friendly greeting identifying the class’s name.""" print(f"Hello, I’m the class ‘{cls.__name__}’!") class UsesMeta(metaclass=Meta): """A class that uses `Meta` as its metaclass.""" As we know, defining a method in a metaclass means that it is inherited by the class, and can be ..

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