From pybites

xpost.py

from datetime import datetime
from dataclasses import dataclass, field

MAX_CONTENT_LENGTH = 280

@dataclass
class XPost:
    content: str
    author: str
    timestamp: str | None = field(default=None)
    hashtags: list[str] = field(default_factory=list)

    def __post_init__(self):
        if len(self.content) > MAX_CONTENT_LENGTH:
            raise ValueError("Content too long")

        if self.timestamp is None:
            self.timestamp = datetime.now().strftime("%Y-%m-%d %H:%M:%S")

        self.hashtags = [f"#{tag.lstrip('#')}" for tag in self.hashtags]

post = XPost(content="Python dataclasses are so nice!",
             author="bbelderbos",
             hashtags=["python", "coding", "#tips"])
print(post)
# XPost(content='Python dataclasses are so nice!', author='bbelderbos',
# timestamp='2024-02-23 14:53:22', hashtags=['#python', '#coding', '#tips'])