Deduplicating Dataset Records | Dataford Interview Questions

Hertz Fleet Operations receives vehicle-event batches that can contain repeated copies of the same event. Deduplicate the batch by retaining the most recently received copy of each logical event.

Implement deduplicate_events(records). A record is a dictionary with these integer fields: rental_id, vehicle_id, event_time, and received_at.

Two records describe the same logical event when their (rental_id, vehicle_id, event_time) values match. For each logical event, keep the record with the greatest received_at. If received_at ties, keep the record that appeared first in the input. Return retained records in their original relative input order.

Formal Specification

Input: records, a list of record dictionaries.
Output: A list containing one retained dictionary per logical event.
Do not modify the input records or their dictionaries.

Constraints

0 <= len(records) <= 100,000
Each record contains integer keys: rental_id, vehicle_id, event_time, and received_at
0 <= each field value <= 10^9
Records with equal logical keys and equal received_at values retain the earliest input occurrence

Function Signature

def deduplicate_events(records):

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