#44 Python Tutorial for Beginners | Decorators
Introduction to Python Decorators
In this video, the presenter introduces decorators in Python and explains how they can be used to add extra features to existing functions without changing their code.
Defining a Division Function
- A division function is defined that takes two parameters and returns their quotient.
- The function is called with two arguments, and the output is printed.
Modifying the Division Function
- A new requirement is introduced where the numerator should always be greater than or equal to the denominator when dividing.
- The logic for swapping the values if necessary is added to the division function.
- The scenario where you don't have access to modify an existing function's code is presented.
Introducing Decorators
- Decorators are introduced as a way of adding extra features to existing functions without modifying their code.
- A decorator named "smart" is defined that accepts a function as its parameter and returns another function that modifies its behavior.
Implementing a Decorator
- An inner function named "inner" is defined inside the smart decorator that performs the desired modification on its input parameters before calling the original function.
- The inner function swaps its input parameters if necessary so that the numerator is always greater than or equal to the denominator when dividing.
Understanding Decorators in Python
In this section, the speaker explains how to use decorators in Python to change the behavior of an existing function at compile time.
Creating a New Function
- A new function is created that takes a function as a parameter.
- A function is defined inside this new function which replaces the code of the original function.
Changing Function Behavior
- Before calling the original function, its definition is changed using the new function.
- This changes the way the original function works and allows for changing its behavior at compile time.
Benefits of Using Decorators
- Decorators allow for changing the behavior of an existing function without modifying its source code.
- They are useful when you want to add functionality to an existing codebase without breaking it.
- Python's functional programming capabilities make it possible to create functions inside other functions, allowing for decorators to be used effectively.