get_ports.py

#!/bin/python3
'''Use netcat to get list of ports numbers.'''


def get_ports():
    from os import system
    system("nc mercury.picoctf.net 22902 > ports.txt &")


if __name__ == '__main__':
    get_ports()

ports_to_key.py

#!/bin/python3
'''Convert port numbers to characters in picoCTF key.'''


def convert_port_numbers():
    key = []
    with open('ports.txt') as txt_file:
        for line in txt_file:
            key.append(chr(int(line[:-2])))
    print(''.join(key))


if __name__ == '__main__':
    convert_port_numbers()