How to create a Python script to monitor and analyze network traffic?

Creating a Python script to monitor and analyze network traffic involves using a Python library called scapy which is used for packet manipulation. However, the extent to which network traffic can be effectively monitored and analyzed using a Python script depends on your understanding of computer networks, protocols and various other parameters.

Here is a simplified script to start capturing packets from your network.

from scapy.all import *

def packet_callback(packet):
    print(packet.show())

def main():
    sniff(prn=packet_callback, count=10)  # adjust count as per your need

if __name__ == "__main__":
    main()

With the script above, 10 packets are sniffed from the network and printed out.

To effectively monitor and analyze traffic, there might be a specific type of packet to watch out for, or certain attributes of the packet that are significant to what’s being monitored or analyzed. For instance, if only packets on port 80 (HTTP) are of interest.

Here's an extended version of the above script that filters for HTTP packets:

from scapy.all import *

def packet_callback(packet):
    if packet[TCP].payload:
        mail_packet = str(packet[TCP].payload)
        if "user" in mail_packet.lower() or "pass" in mail_packet.lower():
            print(f"\n\n[+] Possible username/password > {packet}\n\n")

def main():
    sniff(filter="tcp port 80", prn=packet_callback)

if __name__ == "__main__":
    main()

This script filters for TCP packets where the TCP port is 80 (HTTP). When such a packet is sniffed, it is returned as the argument to the callback function.

This is just a basic network sniffing script in Python and might not cover much of network analysis. However, you can extend it as per your need. If you require more complex tasks like multi-host network traffic recording or statistical analysis of network events, you should use a more robust tool like WireShark, tcpdump etc.

Note: Please be aware that this activity can be illegal if you’re not sniffing packets from a network you have permissions to or you’re using the above method to steal sensitive information. Always use such scripts ethically and responsibly.

Note: Sniffing network traffic may not work across all devices and situations due to restrictions by the network setup. Try different methods and approaches if you encounter difficulties. Run the above scripts in a terminal or command-line interface that has Python installed, not inside an IDE like PyCharm.