How to plan reserved capacity from a CSV in Python

import csv
import io


def plan_reserved_capacity(workloads_csv: str) -> list[dict]:
    """Read a CSV of workloads and return a plan for reserved capacity per service."""
    reader = csv.DictReader(io.StringIO(workloads_csv))
    plan = []
    for row in reader:
        service = row["service"]
        avg_load = float(row["avg_load"])
        peak_load = float(row["peak_load"])
        # Mock rule: reserve 80% of peak load, never below average load
        reserved = max(avg_load, peak_load * 0.8)
        plan.append({
            "service": service,
            "reserved_capacity": round(reserved, 1),
            "headroom": round(peak_load - reserved, 1),
        })
    return plan


if __name__ == "__main__":
    sample_csv = (
        "service,avg_load,peak_load\n"
        "api-gateway,42,58\n"
        "auth,15,25\n"
        "reporting,80,120\n"
    )
    result = plan_reserved_capacity(sample_csv)
    for item in result:
        print(f"{item['service']}: reserved={item['reserved_capacity']}, headroom={item['headroom']}")