Email - Solid

from abc import ABC, abstractmethod

class IContent(ABC):
    def __init__(self, text):
        self.text = text

    @abstractmethod
    def format(self):
        pass

class MyContent(IContent):
    def format(self):
        return ''.join(['<MyML>', self.text, '</MyML>'])

class IProtocol(ABC):
    def __init__(self, text):
        self.text = text

    @abstractmethod
    def format(self):
        pass

class MyProtocol(IProtocol):
    def format(self):
        return ''.join(["I'm" , self.text])


class IEmail(ABC):

    @abstractmethod
    def set_sender(self, sender):
        pass

    @abstractmethod
    def set_receiver(self, receiver):
        pass

    @abstractmethod
    def set_content(self, content):
        pass

class Email(IEmail):
    def __init__(self, protocol):
        self.protocol = protocol
        self.__sender = None
        self.__receiver = None
        self.__content = None

    def set_sender(self, sender):
        self.__sender = sender.format()

    def set_receiver(self, receiver):
        self.__receiver = receiver.format()

    def set_content(self, content):
        self.__content = content.format()

    def __repr__(self):

        template = "Sender: {sender}\nReceiver: {receiver}\nContent: \n{content}"

        return template.format(sender = self.__sender, receiver = self.__receiver, content = self.__content)

email = Email('IM')
email.set_sender('qmal')
email.set_receiver('james')
content = MyContent('Hello, there!')
email.set_content(content)
print(email)