Python Protocol Oriented Programming

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Let me tell ya, this is where things get really interesting (and a little bit ridiculous).

So what exactly is protocol-oriented programming in Python? Well, it’s not about following some fancy dress code or shaking hands with your computer screen. It’s actually a design pattern that focuses on defining interfaces and communication between objects instead of their implementation details. In other words, you’re creating a language for your objects to speak to each other rather than telling them how to do it.

Now, why would we want to do this? Well, let me give you an example. Let’s say you have two classes: `Dog` and `Owner`. In traditional object-oriented programming (OOP), the `Dog` class might have a method called `feed()`, which is implemented by calling some specific feeding instructions for that particular dog breed. But in protocol-oriented programming, we would define an interface or “protocol” for feeding dogs instead of hardcoding it into each individual `Dog` object.

Here’s what the code might look like:

# Define a protocol for feeding dogs
class FeederProtocol(object):
    # Define a method to feed a generic "dog" object
    def feed_dog(self, dog):
        pass # Placeholder for feeding instructions

# Define a Dog class
class Dog(object):
    # Initialize the dog object with no owner
    def __init__(self):
        self.owner = None
        
    # Set the owner of the dog
    def set_owner(self, owner):
        self.owner = owner
        
    # Get food for the dog by calling the FeederProtocol
    def get_food(self):
        return self.owner.feed_dog(self)

# Define an Owner class
class Owner(object):
    # Initialize the owner with an empty list of dogs
    def __init__(self):
        self.dogs = []
        
    # Add a dog to the owner's list of dogs
    def add_dog(self, dog):
        self.dogs.append(dog)
        
    # Feed all dogs owned by the owner
    def feed_all_dogs(self):
        for dog in self.dogs:
            # Call the get_food() method on each dog object to feed them
            print("Feeding {}".format(dog))
            dog.get_food()
            
    # Implement the FeederProtocol for this specific owner's dogs
    def implement_feeder_protocol(self):
        # Define a new class that inherits from FeederProtocol
        class MyFeederProtocol(FeederProtocol):
            # Define how to feed this specific owner's dogs
            def feed_dog(self, dog):
                pass # Placeholder for feeding instructions
        
        # Create an instance of the new FeederProtocol class
        self.feed_protocol = MyFeederProtocol()

In this example, we have defined a `FeedderProtocol` interface that any object can implement if they want to be able to feed dogs. The `Dog` class has been modified to accept an owner and call the owner’s implementation of the feeding protocol when it needs food. And finally, the `Owner` class has implemented its own version of the feeding protocol for all of their dogs.

Protocol-oriented programming in Python is a fun way to think about communication between objects without getting bogged down by specific implementations. Give it a try !

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