Python: Port Scanner -- No port is shown

Question

import socket
from IPy import IP

def scan(target, port_num):
    converted_ip = check_ip(target)
    print(f"\n [-_0 Scanning Target]: {target}")
    for port in range(1, port_num):
        scan_port(converted_ip, port)

def check_ip(ip):
    try:
        IP(ip)
        return (ip)
    except ValueError:
        return socket.gethostbyname(ip)

def get_banner(s):
    return s.recv(1024)

def scan_port(ipaddress, port):
    try:
        sock = socket.socket()
        sock.settimeout(0.5)
        sock.connect((ipaddress, port))
        try:
            banner = get_banner(sock)
            print(f"[+] Open Port {port}: {banner.decode().strip()}")
        except:
            print(f"[+] open Port {port}")
    except:
        pass

if __name__ == "__main__":
    targets = input("[+] Enter Targets to Scan (split multiple targets with ,): ")
    port_num = input("Enter Numbers of Ports you want to Scan: ")
    if ',' in targets:
        for ip_add in targets.split(","):
            scan(ip_add.strip(" "), port_num)
    else:
        scan(targets, port_num)

guys, I wrote a simple port scanner as above, but whenever I tried to scan the ip address(IPv$) of my computer, or linux system in my vitual machine, no open port is shown.

Q1. Can someone tell me how to fix this? Thank you for your help.