Dice gamecscs

import os.path, time, random
from datetime import datetime
from time import sleep
now = datetime.now()
zero = ":"
if len(str(now.minute)) == 1:
    zero = (":"+str(0))

def welcome():
    print("Hi! Welcome to the dice game, the current time is %s%s%s and the date is %s/%s/%s\n" % (now.hour, zero, now.minute, now.day, now.month, now.year),".")
    option = str(input("Please choose what option you would like to select:\n1. Register\n2. Login\n3. Quit\n"))
    if   option == "1":  register()
    elif option == "2":  login()
    else:                quit

def register():
    username = str(input("Please create a username:\n"))
    if not os.path.isfile(username+".txt"):
        password = str(input("Please input a password:\n"))
        confirm_password = str(input("Please confirm your password:\n"))
        if password == confirm_password:
            user_file = open(username+".txt", "w")
            user_file.write(password)
            user_file.close()
            print("You have now successfully registered and you are ready to play!")
            welcome()
        else:
            print("Failed to confirm password, please try again")
            register()
    else:
        print(username,"already exists, please try using a different one.")
        register()

def login():
    username = str(input("Please input your username:\n"))
    if os.path.isfile(username+".txt"):
        input_password = str(input("Please input your password:\n"))
        user_file = open(username+".txt", "r")
        read_file = user_file.readlines()
        password = read_file[0]
        if password == input_password:
            print("You have now logged in as",username)
        else:
            print("Sorry but that is the wrong password, please try again")
            login()
    else:
        print("There is no Username called:",username)

welcome()

person1_name = input("Player 1, what is your name: ")
person2_name = input("Player 2, what is your name: ")

names  = [person1_name, person2_name]
totals = [0, 0]
rolls = 1
maxrolls = 5

def roll():

    random.seed(datetime.now())
    player = 0
    while player <= 1:
        number1, number2 = random.randint(1,6), random.randint(1,6)
        print(names[player], "- 1st roll =", number1, "and 2nd roll =", number2)

        total = number1 + number2

        if total % 2 == 0:
            total += 10

        else:
            if total < 4:
                total = 0
            else:
                total -= 5

        print(names[player]," has rolled", total, "points.")

        totals[player] += total
        player += 1
    sleep(2)

def checkscores():
    print("\nFinal results: ", names[0], totals[0],"-",totals[1] , person2_name)
    if totals[0] > totals[1]:
        print(person1_name," is the winner! ")
    elif totals[0] == totals[1]:
        print("\nIt's now sudden death!")
        roll()
        checkscores()
    else:
        print(person2_name," is the winner! ")

while rolls <= maxrolls:
    print("\nRoll", rolls)
    rolls += 1
    roll()

checkscores()