Python script works when I run from IDLE but not in command line?

I'm working on a school project, and we have to make a script. Basically, whenever I'm in IDLE and I press F5 to run the script everything works fine, but when I double click the python file itself and go into command line, I only get to input one thing (R or L) and then the window closes. Why is this ? I think one of the requirements for the assignment is that it need to be executed in Command Line, so this is why I'm asking. Here is my script (it's not finished yet)

import os
import csv
import sys


def main():
    menu()



def menu():
    print ("******MAIN MENU******")
    print()
    veryFirstChoice = input("Would you like to register an account, or log in? Type R to register and L to log in ").upper()
    if veryFirstChoice == "R":
        register()
    elif veryFirstChoice == "L":
        login()

def login():
    username = input("Please enter your username")
    password = input("Please enter your password")  
    for line in open("accountfile.txt","r").readlines():
        login_info = line.split()
        if username == login_info[0] and password == login_info[1]:
            print("Correct credentials!")
            return quiz()
    print("Incorrect credentials,please try again. ")
    return login()

def register():
    username = input("Please input the first 3 letters of your first name and your age ")
    password = input("Please input your desired password ")
    file = open("accountfile.txt","a")
    file.write(username)
    file.write(" ")
    file.write(password)
    file.write("\n")
    file.close()
    menu()

def quiz():
    choice1 = input ("""Would you like to take the Chemistry Quiz,or the Computer Science quiz ? Type in CH for Chemistry or CS for Computer Science """).upper()
    score = 0

    if choice1 == "CH":
        choice2 = input ("Would you like to do the easy, medium or hard questions ?").lower()
        if choice2 == "easy":
            load_profile = open("chemistryquiz.txt","r")
            lines = load_profile.read().splitlines()
            question1 = lines[4]
            question2 = lines[5]
            question3 = lines[6]
            question4 = lines[7]
            question5 = lines[8]
            print (question1)
            answer1 = input("Please enter your answer ").upper()
            if answer1 != "A":
                print ("You got the wrong answer, your score is", score)
            else:
                score1 = (score+1)
                print ("Your score is", score1)
            print (question2)
            answer2 = input("Please enter your answer ").upper()
            if answer2 != "A":
                score1 = score1
                print ("You got the wrong answer, your score is", score1)

            else:
                score2 = (score1+1)
                print ("Your score is", score2)
            print (question3)
            answer3 = input("Please enter your answer ").upper()
            score2 = score1
            if answer3 != "A":
                score3 = score2
                print ("You got the wrong answer, your score is", score3)
            else:
                score3 = (score2+1)
                print ("Your score is", score3)
            print (question4)
            answer4 = input("Please enter your answer ").upper()
            if answer4 != "A":
                score4 = score3
                print ("Wrong answer, your score is ", score4)
            else:
                score4 = (score3+1)
                print ("Your score is", score4)
            print (question5)
            answer5 = input("Please enter your answer ").upper()
            if answer5 != "A":
                score5 = score4
                print ("You got the wrong answer, your score is ", score5)
            else:
                score5 = (score4+1)
                print ("Well done, your score is ", score5)
        if choice2 == "medium":
            load_profile = open("chemistryquiz.txt","r")
            lines = load_profile.read().splitlines()
            question1 = lines[13]
            question2 = lines[14]
            print (question1)
            answer1 = input("Please enter answer ").upper()
            if answer1 != "A":
                score1 = score
                print ("Wrong answer ", score1)
            else:
                score1 = (score+1)
                print ("Noice, score is ", score1)

main()