Use Python dataclass to autogenerate timestamp and sequence id on an object.

dataclass_sample.py

from dataclasses import dataclass, field
from itertools import count
from datetime import datetime

counter = count()


@dataclass
class Event:
    message: str
    create_at: datetime = field(default_factory=datetime.now)
    index: int = field(default_factory=lambda: next(counter))
    
Event('foo')
Event('bar')

# Event(message='foo', create_at=datetime.datetime(2018, 9, 21, 13, 5, 23, 781750), index=0)
# Event(message='bar', create_at=datetime.datetime(2018, 9, 21, 13, 5, 23, 781750), index=1)