portscanner.py

import socket
from IPy import IP

class PortScan():
    banners = []
    open_ports = []

    def __init__(self, target, port_number):
        self.target = target
        self.port_number = port_number

    def scan(self):
        for port in range(1, self.port_number):       
            self.scan_port(port)  

    def scan_port(self, port):
        """Verify if the given port of the given ipaddress is opened or closed"""
        try:
            target_ip = self.check_ip()
            sock = socket.socket()
            sock.settimeout(0.5) # Lower the timeout lower the accuracy of the scan 
            sock.connect((target_ip, port))
            self.open_ports.append(port)
            try:
                self.banner.append(sock.recv(1024).decode().strip('\n').strip('\r'))
            except:
                self.banner.append(None)
            sock.close()
        except:
            pass

    def check_ip(self):
        """Check if the given ip is valid or if it is an hostname. If it is an hostname, it will be resolved to an ip."""       
        try:
            IP(self.target)
            return self.target
        except ValueError:
            return socket.gethostbyname(self.target)