네트워크 속도 추정기

def estimate_transfer_time(file_size_mb: float, speed_mbps: float, efficiency: float = 0.85) -> dict:
    """
    Estimate file transfer time.
    file_size_mb: file size in megabytes
    speed_mbps:   connection speed in megabits per second
    efficiency:   real-world factor (0.0–1.0), default 0.85
    """
    file_bits = file_size_mb * 8  # convert MB to Mb
    effective_speed = speed_mbps * efficiency
    seconds = file_bits / effective_speed

    return {
        "seconds": round(seconds, 2),
        "minutes": round(seconds / 60, 2),
        "hours":   round(seconds / 3600, 4),
    }

# Common connection speeds (Mbps)
speeds = {
    "3G":          7.2,
    "4G LTE":      50,
    "5G":          400,
    "Wi-Fi 5":     600,
    "Ethernet 1G": 1000,
}

file_size_gb = 1.0
file_size_mb = file_size_gb * 1024

print(f"File size: {file_size_gb} GB ({file_size_mb} MB)")
for name, speed in speeds.items():
    result = estimate_transfer_time(file_size_mb, speed)
    print(f"{name:15s} @ {speed:>6} Mbps: {result['seconds']:>8.1f}s  ({result['minutes']:.1f} min)")