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Implement Exactly-Once Transaction Log in Python

A mock transaction log that deduplicates transaction IDs so each is recorded only once, with a dataclass for records and simple in-memory storage.

transactions deduplication dataclass

Python

from dataclasses import dataclass
from typing import Dict, Optional


@dataclass
class TxnRecord:
    txn_id: str
    status: str


class ExactlyOnceTxnLog:
    def __init__(self) -> None:
        self._log: Dict[str, TxnRecord] = {}
        self._processed_ids: set = set()

    def record(self, txn_id: str, status: s…

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