__bases__

Definition

__bases__ is a term used in the context of object-oriented programming, specifically in the discussion of inheritance and multiple inheritance. It refers to the parent or superclass(es) from which a derived or subclass inherits properties and methods.

5 Must Know Facts For Your Next Test

1. The __bases__ attribute of a class in Python is a tuple that contains the base classes (superclasses) from which the class inherits.
2. In single inheritance, a class has only one base class, and the __bases__ attribute will contain a single-element tuple.
3. In multiple inheritance, a class can have multiple base classes, and the __bases__ attribute will contain a tuple with all the inherited superclasses.
4. The order of the base classes in the __bases__ tuple determines the method resolution order (MRO), which is the sequence in which the interpreter searches for methods in the inheritance hierarchy.
5. The __bases__ attribute can be used to inspect the inheritance hierarchy of a class and understand its relationships with other classes.

Review Questions

• Explain the purpose of the __bases__ attribute in the context of inheritance basics.
  • The __bases__ attribute in Python is used to represent the parent or superclass(es) from which a derived or subclass inherits. It is a tuple that contains the base classes of a given class. This information is crucial for understanding the inheritance hierarchy of a class and how it acquires properties and methods from its superclasses. The __bases__ attribute allows you to inspect the inheritance structure and determine the relationships between classes in an object-oriented program.
• Describe how the __bases__ attribute is used in the context of multiple inheritance and mixin classes.
  • In the context of multiple inheritance, the __bases__ attribute of a class will contain a tuple with all the superclasses from which the class inherits. This allows the subclass to access and utilize the methods and properties of multiple parent classes, a feature known as multiple inheritance. Additionally, mixin classes, which are classes designed to provide additional functionality to a subclass, will also be represented in the __bases__ attribute when the subclass inherits from them. Understanding the __bases__ attribute is crucial for navigating the complex inheritance hierarchies that can arise in multiple inheritance and mixin class scenarios.
• Analyze how the order of base classes in the __bases__ attribute can impact method resolution in a class hierarchy.
  • The order of the base classes in the __bases__ attribute determines the method resolution order (MRO), which is the sequence in which the interpreter searches for methods in the inheritance hierarchy. This order can have a significant impact on the behavior of a class, as the first matching method found in the MRO will be the one that is executed. In the context of multiple inheritance, carefully considering the order of base classes in the __bases__ attribute is essential for ensuring the desired method resolution and avoiding unexpected conflicts or ambiguities in the class hierarchy.

Related terms

Inheritance:

The mechanism by which a subclass acquires the properties and methods of a superclass, allowing code reuse and the creation of hierarchical class structures.

Superclass:

The class from which a subclass inherits, also known as the parent class or base class.

Subclass:

The class that inherits from a superclass, also known as the child class or derived class.