Can I Inherit Variable (Class Object) to a Class in Python?

Discover if it is possible to inherit a variable (class object) in Python and understand how objects work in the language with a practical example.
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Can I Inherit Variable (Class Object) to a Class in Python?

In Python, the object-oriented programming paradigm allows developers to create classes and use them to encapsulate data and behaviors. A common question that arises among newcomers, especially those following guides like PyQT, is whether they can inherit a variable (class object) to a class. This post will explore this concept thoroughly, providing clarity on the use of both built-in and user-defined classes.

Understanding the Basics

When dealing with classes in Python, it's crucial to recognize the nature of classes and objects. Here’s a concise breakdown:

Class: A blueprint for creating objects, containing methods (functions) and attributes (variables).

Object: An instance of a class. Every class in Python is itself an instance of the type class.

For instance, in PyQT (a popular GUI framework), you might find yourself dealing with classes like QMainWindow. But what about when you want to use variables that reference other classes? This commonly occurs when integrating design files and UI classes into your Python application.

The PyQT Example

In the provided example, you are creating a class that inherits from QMainWindow, which is standard practice in PyQT applications. Here's a snippet of the relevant code:

[[See Video to Reveal this Text or Code Snippet]]

What’s Happening with form_class?

You might be wondering why form_class, which is a variable, is appearing in the parentheses of the class definition like so: class WindowClass(QMainWindow, form_class). Let’s clarify this:

QMainWindow is a class; when you derive a new class (WindowClass), you typically want it to inherit all properties and methods of QMainWindow.

Using Type Checking

When you evaluated the types using:

[[See Video to Reveal this Text or Code Snippet]]

The outputs are:

[[See Video to Reveal this Text or Code Snippet]]

This output indicates that form_class behaves like a class (instance of type) and has a method resolution order (MRO), which is also a fundamental characteristic of classes.

Why This Works

In Python, every class you define is an instance of type, and variables can 'reference' these classes. Therefore, it is completely valid to use a variable in the class inheritance list. Doing so opens up more dynamic and flexible programming patterns, such as using form classes loaded from design files.

Key Takeaways

All classes are objects in Python: They can be referenced by variables and used interchangeably within class definitions.

MRO: Understanding method resolution order helps clarify how Python determines which method to invoke in inherited classes.

Conclusion

In conclusion, yes, you can inherit a variable (class object) to a class in Python. This flexibility is one of the many features that make Python an excellent choice for both beginners and experienced developers. Understanding how Python treats classes and objects can significantly enhance your coding efficiency and application design.

If you have further questions or examples you’d like to share, feel free to drop them in the comments below!