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Execute Parent Class Functions Like a Parent Object in Python

Discover how to call a Parent class method as if you were using a Parent object in Python. Learn strategies like name mangling and the use of `__class__` to achieve your goals. --- This video is based on the question https://stackoverflow.com/q/75452941/ asked by the user 'Patrick' ( https://stackoverflow.com/u/563130/ ) and on the answer https://stackoverflow.com/a/75453000/ provided by the user 'jsbueno' ( https://stackoverflow.com/u/108205/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions. Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: In Python how to call Parent class function as if I were Parent object Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l... The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license. If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com. --- Calling Parent Class Functions as If You Were a Parent Object in Python When working with classes and inheritance in Python, you might run into situations where you want to call a method from a parent class in a child class, while using the same method name in both classes. This can lead to unexpected behavior if the child class overrides the method, making it tricky to execute the parent's method directly. In this guide, we’ll explore how to properly structure your classes and utilize advanced Python techniques to resolve this issue without renaming your methods. The Problem: Inheritance and Method Overriding Let’s consider a scenario where you have a Parent class and a Child class, both containing an initialization method (__init__) that calls a function named fct. The goal is to ensure that when the child class is instantiated, it first executes the parent class's function before performing its own operations. However, when you call super().__init__(), it inadvertently calls the child's own fct method instead of the parent's. Here's a simplified version of the classes in question: [[See Video to Reveal this Text or Code Snippet]] The Challenge The issue arises because the child class overrides the fct method. Without being able to call the parent's method directly, you'll need to find an effective workaround. Solution 1: Using Name Mangling One effective strategy is to leverage Python's name mangling feature by prefixing your method's name with two underscores (__). This causes Python to change the actual method name when it's stored in the class, preventing conflicts between the child and parent methods. Here's how you can implement it: [[See Video to Reveal this Text or Code Snippet]] How Name Mangling Works When you use a double underscore prefix, Python internally renames the method: Parent's __fct becomes Parent._Parent__fct Child's __fct becomes Child._Child__fct This allows both methods to coexist independently while still being accessible within their respective classes. Some documentation may refer to the dual underscore methods as "private methods", but it’s important to note that while this can mimic privacy, it also serves to resolve method name conflicts. Solution 2: Using _class_ to Access Parent Methods without Name Mangling If you prefer not to use name mangling, another approach is to explicitly retrieve the parent class's method using the _class_ attribute. This attribute helps access class-level methods without interference from method overrides. [[See Video to Reveal this Text or Code Snippet]] Important Notes on _class_ The usage of _class_ allows you to reference the current class and access its methods directly. Since methods are retrieved from the class object, you must pass the instance (self) as an argument when calling these methods. Conclusion In Python, managing method calls in an inheritance hierarchy can sometimes be a challenge, especially when dealing with method overriding. However, with techniques like name mangling and using __class__, you can effectively manage your method calls without needing to rename your functions. By applying these strategies, you can create clean, organized, and maintainable class structures that fulfill your intended design. Whether you choose to use name mangling or the _class_ method, each approach provides a way to ensure that your parent class functions are called correctly while preserving the integrity of your code.