Python Dynamic Method Addition: Expand Class Behavior

Python Metaprogramming: Exercise-6 with Solution

Adding Methods Dynamically:

Write Python a function "add_method" that takes a class, a method name, and a method, and adds that method to the class.

Sample Solution:

Python Code :

# Function to add a method to a class dynamically
def add_method(cls, method_name, method):
    # Use setattr to add the method to the class
    setattr(cls, method_name, method)

# Define an empty class
class MyClass:
    pass

# Define a method to be added to the class
def greet(self):
    return "Hello, dynamically added method!"

# Add the 'greet' method to 'MyClass' dynamically
add_method(MyClass, 'greet', greet)

# Test the dynamic method addition
# Create an instance of MyClass
instance = MyClass()
# Call the dynamically added 'greet' method
print(instance.greet())  # Output: "Hello, dynamically added method!" 

Output:

Hello, dynamically added method!

Explanation:

• Function Definition:
• "add_method" takes 'cls' (the class to add the method to), 'method_name' (the name of the method), and 'method' (the method function itself).
• Add Method:
• setattr(cls, method_name, method) adds the method to the class using the given method name.
• Class Definition:
• "MyClass" is defined as an empty class.
• Method Definition:
• "greet" is a function that returns the string "Hello, dynamically added method!".
• Add Method to Class:
• add_method(MyClass, 'greet', greet) adds the "greet" method to "MyClass" dynamically.
• Testing:
• An instance of "MyClass" is created.
• The "greet" method is called on the instance, returning "Hello, dynamically added method!".

Python Code Editor :

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