Example for an User class in Python with dataclasses

user.py

from dataclasses import dataclass

DOMAIN = 'example.com'

@dataclass
class User:
    user_id: str = None
    name: str = None
    email: str = None
    role: str = 'standard'

    def __post_init__(self):
        # The param 'user_id' MUST be passed. The rest are optional.
        if not self.user_id:
            raise ValueError('Parameter user_id is missing')
        if not self.name:
            self.name = self.id_to_name(self.user_id)
        if not self.email:
            self.email = self.id_to_email(self.user_id)

    @staticmethod
    def id_to_name(user_id: str) -> str:
        # 1- Split 'user_id' by the . into a list of words ([name, surname])
        # 2- Iterate those words and capitalize them ([Name, Surname])
        # 3- Join those words into a single string, but separated by 1 space
        name = ' '.join(word.title() for word in user_id.split('.'))
        return name

    @staticmethod
    def id_to_email(user_id: str) -> str:
        email = user_id + '@' + DOMAIN
        return email

    @staticmethod
    def email_to_id(email: str) -> str:
        if '@' not in email:
            raise ValueError('The character @ at the parameter email is missing')
        user_id = email.split('@')[0]
        return user_id

    @staticmethod
    def from_dict(source: dict):
        user = User(**source)
        return user

    def to_dict(self) -> dict:
        return self.__dict__