Build a Network Ping Monitor in Python

import subprocess
import time

def ping_host(host, count=4):
    """Ping a host and return the results."""
    try:
        # Platform-independent ping command
        cmd = ["ping", "-c", str(count), host]
        result = subprocess.run(cmd, capture_output=True, text=True, timeout=10)
        return result.stdout, result.returncode
    except subprocess.TimeoutExpired:
        return "Ping timed out", 1
    except FileNotFoundError:
        return "Ping command not found", 1

def monitor_host(host, interval=5, pings_per_check=3):
    """Monitor network connectivity to a host."""
    print(f"Monitoring {host} every {interval} seconds...")
    try:
        while True:
            output, return_code = ping_host(host, pings_per_check)
            timestamp = time.strftime("%Y-%m-%d %H:%M:%S")
            
            if return_code == 0:
                # Extract latency from ping output
                latency_line = [line for line in output.split('\n') 
                              if 'time=' in line or 'time<' in line]
                print(f"[{timestamp}] ✓ {host} is reachable | {latency_line[-1] if latency_line else 'OK'}")
            else:
                print(f"[{timestamp}] ✗ {host} is NOT reachable")
            
            time.sleep(interval)
    except KeyboardInterrupt:
        print("\nMonitoring stopped by user")

if __name__ == "__main__":
    # Monitor Google DNS for demonstration
    monitor_host("8.8.8.8", interval=3, pings_per_check=2)