Machines on a Repeating Maintenance Rotation

Problem

Two CSV files describe a maintenance system. `machines.csv` holds each machine (`machine_id`, `machine_name`, `plant`); `maintenance_logs.csv` records each task performed on a machine (`log_id`, `machine_id`, `task`, `done_on`, `crew_hours`). Ordering each machine's logs by date, a machine follows a 'repeating rotation' when its tasks cycle through at least three distinct task types in a fixed order that repeats for at least two full cycles (so at least six logged tasks), with no gap longer than two days between consecutive tasks. For each such machine return one cycle's length (number of tasks before the pattern repeats) as `cycle_length` and the total `crew_hours` across the chained tasks as `total_hours`. Sort by `cycle_length` descending, then by `total_hours` descending.

Input data

Example rows — the live problem includes the full dataset.

Expected output

Your answer should return 2 rows with the columns machine_name, cycle_length, total_hours.

Starter code (Pandas (Python))

import pandas as pd

def find_repeating_rotations(machines, maintenance_logs) -> pd.DataFrame:
    # Your code here
    return machines

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