class Base(): """ My base class """ __nb_instances = 0 def __init__(self): Base.__nb_instances += 1 self.id = Base.__nb_instancesclass User(Base): """ My User class """ def __init__(self): super().__init__() self.id = 89u = User()print(u.id)
Question
class Base(): """ My base class """ __nb_instances = 0 def init(self): Base.__nb_instances += 1 self.id = Base.__nb_instancesclass User(Base): """ My User class """ def init(self): super().init() self.id = 89u = User()print(u.id)
Solution
The code you provided is written in Python. It defines two classes: Base and User. User is a subclass of Base.
Here's a step-by-step explanation of what the code does:
-
The
Baseclass is defined with a private class variable__nb_instanceswhich is initially set to 0. This variable is used to keep track of the number of instances of theBaseclass. -
The
Baseclass has an__init__method (constructor) which increments__nb_instancesby 1 every time a new instance ofBase(or its subclass) is created. It also assigns the current value of__nb_instancesto the instance variableself.id. -
The
Userclass is defined as a subclass ofBase. It also has an__init__method which first calls the__init__method of theBaseclass usingsuper().__init__()and then setsself.idto 89. -
An instance
uof theUserclass is created. -
The
idof theUserinstanceuis printed.
The output of the code will be 89 because although the Base class's __init__ method sets self.id to 1, the User class's __init__ method overrides this by setting self.id to 89.
Similar Questions
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