while True:
    print "1. Login"
    print "2. Register"
    print "3. View user"

    pilihan = raw_input("Pilih opsi [1,2,3]:")


    def login(user, password):
        try:
            with open("users.txt", 'r') as f:
                for line in f:
                    login = line.split()
                    if login[0] == user and login[1] == password:
                        return True
        except IOError:
            print "file tidak ada"


    if pilihan == "1":
        user = raw_input('username:')
        password = raw_input('password:')
        if login(user, password):
            print "Welcome %s" % user
        else:
            print "User tidak ditemukan"
    elif pilihan == "2":
        username = raw_input('username:')
        password = raw_input('password:')
        try:
            with open("users.txt", 'a') as f:
                f.write(username + " ")
                f.write(password + "\n")
        except IOError:
            print "File tidak ada"
    elif pilihan == "3":
        list_user = []
        try:
            with open("users.txt", 'r') as f:
                for line in f:
                    row = []
                    data_dict = {}
                    data = line.split()
                    data_dict['username'] = data[0]
                    data_dict['password'] = data[1]
                    row.append(data_dict)
                    list_user.append(row)
        except IOError:
            print "File tidak ditemukan"
        print list_user
    else:
        print "Pilihan Anda tidak ada"
        break