emails_mustafafurkan_yilmaz.py

import re

class Emails(list):
    def __init__(self, emails):
        # 1. Validate that all inputs are strings
        if not all(isinstance(email, str) for email in emails):
            raise ValueError("All items must be strings.")

        # 2. Validate email format using Regex
        # Pattern checks for: non-empty-chars @ non-empty-chars . non-empty-chars
        pattern = re.compile(r"^[^@]+@[^@]+\.[^@]+$")
        for email in emails:
            if not pattern.match(email):
                raise ValueError(f"Invalid email address: {email}")

        # 3. Remove duplicates while preserving order
        # dict.fromkeys() is a fast way to remove duplicates in Python 3.7+
        unique_emails = list(dict.fromkeys(emails))

        # Initialize the list with the processed data
        super().__init__(unique_emails)
        
        # 4. Create a .data attribute to satisfy test_validate_duplicates
        # Since this class inherits from list, 'self' holds the data.
        # We point .data to self to allow .data.count() to work as expected by the test.
        self.data = self

    def validate(self):
        """
        Existence of this method is required by test_validate.
        Actual validation logic is handled in __init__ to ensure 
        ValueErrors are raised during instantiation.
        """
        return True

    def __repr__(self):
        # Returns a string representation that can reproduce the object
        # e.g., Emails(['a@b.com'])
        return f"Emails({super().__repr__()})"

    def __str__(self):
        # String representation of the list
        return super().__repr__()