Dataclasses

Data behavior

from dataclasses import dataclass
from functools import cached_property

from email_tools.service import EmailService

SMTP_SERVER = "smtp.gmail.com"
PORT = 465
EMAIL = "[email protected]"
PASSWORD = "password"


@dataclass
class Stats:
    age: int
    gender: str
    height: float
    weight: float
    blood_type: str
    eye_color: str
    hair_color: str

    @cached_property
    def bmi(self) -> float:
        return self.weight / (self.height**2)

    def get_bmi_category(self) -> str:
        if self.bmi < 18.5:
            return "Underweight"
        elif self.bmi < 25:
            return "Normal"
        elif self.bmi < 30:
            return "Overweight"
        else:
            return "Obese"


@dataclass
class Address:
    address_line_1: str
    address_line_2: str
    city: str
    country: str
    postal_code: str

    def get_full_address(self) -> str:
        return f"{self.address_line_1}, {self.address_line_2}, {self.city}, {self.country}, {self.postal_code}"


@dataclass
class Person:
    name: str
    address: Address
    email: str
    phone_number: str
    stats: Stats

    def split_name(self) -> tuple[str, str]:
        first_name, last_name = self.name.split(" ")
        return first_name, last_name

    def update_email(self, email: str) -> None:
        self.email = email
        # send email to the new address
        email_service = EmailService(
            smtp_server=SMTP_SERVER,
            port=PORT,
            email=EMAIL,
            password=PASSWORD,
        )
        email_service.send_message(
            to_email=self.email,
            subject="Your email has been updated.",
            body="Your email has been updated. If this was not you, you have a problem.",
        )


def main() -> None:
    # create a person
    address = Address(
        address_line_1="123 Main St",
        address_line_2="Apt 1",
        city="New York",
        country="USA",
        postal_code="12345",
    )
    stats = Stats(
        age=30,
        gender="Male",
        height=1.8,
        weight=80,
        blood_type="A+",
        eye_color="Brown",
        hair_color="Black",
    )
    person = Person(
        name="John Doe",
        email="[email protected]",
        phone_number="123-456-7890",
        address=address,
        stats=stats,
    )

    # compute the BMI
    bmi = stats.bmi
    print(f"Your BMI is {bmi:.2f}")

    # update the email address
    person.update_email("[email protected]")


if __name__ == "__main__":
    main()

Encapsulation

class Person:
    def __init__(self, name: str, age: int, ssn: str):
        self.name = name
        self.age = age
        self.__ssn = ssn  # Private attribute

    # Public method
    def display_info(self) -> None:
        print(f"Name: {self.name}")
        print(f"Age: {self.age}")
        print(f"SSN: {self.ssn}")

    @property
    def ssn(self) -> str:
        masked_ssn = "XXX-XX-" + self.__ssn[-4:]
        return masked_ssn


def main() -> None:
    # Creating an instance of the Person class
    person1 = Person("John Doe", 30, "123-45-6789")

    # Accessing public method
    person1.display_info()

    # Output:
    # Name: John Doe
    # Age: 30
    # SSN: XXX-XX-6789

    # Accessing private attribute or method directly will raise an AttributeError
    # print(person1.__ssn)  # This will raise an AttributeError
    # print(person1._Person__ssn)  # This will work so it's not truly private


if __name__ == "__main__":
    main()