import ftplib

loginData = input("[username@hostname:port]\n")
username = loginData.split("@")[0]
hostname = loginData.split("@")[1].split(":")[0]
port = int(loginData.split("@")[1].split(":")[1])
ftp = ftplib.FTP()
ftp.connect(hostname, port)
password = input("password : ")
ftp.login(username, password)

def getFile(ftp, filename):
    try:
        ftp.retrbinary("RETR " + filename ,open(filename, 'wb').write)
    except ftplib.error_perm as e:
        print(e)

while True:
    print("\n[FILE LIST]")
    ftp.mlsd()
    requestFile = input("Name of file to request : ")
    getFile(ftp, requestFile)

ftp.quit()