from socket import socket
from select import select

tmout = 1
chunk = 300

def scan_chunk(host, begin_port, end_port):
    socks = []
    for port in range(begin_port, end_port):
        sock = socket()
        sock.setblocking(False)
        try:
            sock.connect((host, port))
        except BlockingIOError:
            pass
        socks.append(sock)
    r, w, x = select([], socks, [], tmout)
    for sock in w:
        port = sock.getpeername()[1]
        print(port, 'connected')
    for sock in socks:
        sock.close()

host = input('address: ')
begin_port = int(input('port to start scanning from: '))
end_port = int(input('to :'))

for port in range(begin_port, end_port, chunk):
    scan_chunk(host, port, min(end_port, port + chunk))