How can I return my code to the start of the code?

Question

I've been trying to return my code to the beginning after the player chooses 'yes' when asked to restart the game. How do I make the game restart?

I've tried as many solutions as possible and have ended up with this code. Including continue, break, and several other obvious options.

import time
def start():
    score = 0
    print("Welcome to Atlantis, the sunken city!")
    time.sleep(1.5)
    print("You are the first adventurist to discover it!")
    time.sleep(1.5)
    print("Do you explore or talk to the merpeople?")
    time.sleep(1.5)
    print("Type 1 to explore Atlantis alone.")
    time.sleep(1.5)
    print("Type 2 to talk to the resident merpeople.")

start()

def surface():
    print("You return to the surface.")
    print("When you go back to Atlantis it's gone!")
    print("Your findings are turned to myth.")
    print("The end!")
    print("Wanna play again?If you do, type yes! If you wanna leave, type no!")
    score = -1

def castle():
    print("The merpeople welcome you to their castle.")
    print("It is beautiful and you get oxygen.")
    print("Now that you have your oxygen, you can either go to the surface or explore Atlantis alone.")
    score = 1
    print("To explore alone enter 5. To go to the surface enter 6.")


def drowndeath():
    print("You begin to explore around you.")
    print("You avoid the merpeople who avoid you in return.")
    print("But, OH NO, your oxygen begins to run out!")
    print("You run out of air and die.")
    print("Wanna play again?If you do, type yes! If you wanna leave, type no!")
    score = 4

def merpeople():
    print("The merpeople talk kindly to you.")
    print("They warn you that your oxygen tank is running low!")
    print("You can follow them to their castle or go back to the surface.")
    print("Type 3 to go to the castle or 4 to go to the surface.")
    score = 5

def alone():
    print("You begin to explore alone and discover a secret caven.")
    print("You go inside and rocks trap you inside!")
    print("You die underwater.")
    print("Wanna play again?If you do, type yes! If you wanna leave, type no!")
    score = 6

def famous():
    print("You come back to land with new discoveries!")
    print("Everyone loves you and the two worlds are now connected!")
    print("You win!")
    print("Wanna play again?If you do, type yes! If you wanna leave, type no!")


def choice_made():
    choice = input("Make your decision!\n ")
    if choice == "1":
        drowndeath()
    elif choice == "2":
        merpeople()
    else:
        print("Please enter a valid answer.")
        choice_made()

choice_made()

def choice2_made():
    choice2 = input("What do you do?\n ")
    if choice2 == "4":
        surface()
    elif choice2 == "3":
        castle()
    elif choice2 == "yes":
        start()
    elif choice2 == "no":
        exit()
    else:
        print("Please enter a valid answer.")
        choice2_made()
choice2_made()

def choice3_made():
    choice3 = input("Make up your mind!\n ")
    if choice3 == "5":
        alone()
    if choice3 == "6":
        famous()
    else:
        print("Please enter a valid answer.")
        choice3_made()
choice3_made()

def restart_made():
    restart = input("Type your answer!\n ")
    if restart == "yes":
        sys.exit()
    elif restart == "no":
        exit()
    else:
        print("Please choose yes or no!")
        restart_made()

restart_made()

while True:

    choice = input("Make your decision!\n ")
    if choice == "1":
        drowndeath()
    elif choice == "2":
        merpeople()    
    else:
        print("Please enter a valid answer.")
        choice_made()

choice_made()

while True:
    choice2 = input("What do you do?\n ")
    if choice2 == "4":
        surface()
    if choice2 == "3":
        castle()
    else:
        print("Please enter a valid answer.")
        choice2_made()
choice2_made()

while True:
    choice3 = input("Make up your mind!\n ")
    if choice3 == "5":
        alone()
    if choice3 == "6":
        famous()
    if choice3 == "1":
        drowndeath()
    if choice3 == "2":
        merpeople()
    else:
        print("Please enter a valid answer.")
        choice3_made()
choice3_made()

while True:
    restart = input("Type your answer!\n ")
    if restart == "yes":
        sys.exit()
    elif restart == "no":
        exit()
    else:
        print("Please choose yes or no!")
        restart_made()

restart_made()

I want for my code to restart completely when 'yes' is typed after given the option.

Answer 1

You have two main options. First option: make a main function that, when called, executes your script once. Then, for the actual execution of the code, do this:

while True:
    main()
    if input("Would you like to restart? Type 'y' or 'yes' if so.").lower() not in ['y', 'yes']:
        break

Second, less compatible option: use os or subprocess to issue a shell command to execute the script again, e.g os.system("python3 filename.py").

EDIT: Despite the fact this is discouraged on SO, I decided to help a friend out and rewrote your script. Please do not ask for this in the future. Here it is:

import time, sys
score = 0
def makeChoice(message1, message2):
    try:
        print("Type 1 "+message1+".")
        time.sleep(1.5)
        print("Type 2 "+message2+".")
        ans = int(input("Which do you choose? "))
        print()
        if ans in (1,2):
            return ans
        else:
            print("Please enter a valid number.")
            return makeChoice(message1, message2)
    except ValueError:
        print("Please enter either 1 or 2.")
        return makeChoice(message1, message2)
def askRestart():
    if input("Would you like to restart? Type 'y' or 'yes' if so. ").lower() in ['y', 'yes']:
        print()
        print("Okay. Restarting game!")
        playGame()
    else:
        print("Thanks for playing! Goodbye!")
    sys.exit(0)
def surface():
    print("You return to the surface.")
    print("When you go back to Atlantis it's gone!")
    print("Your findings are turned to myth.")
    print("The end!")
def castle():
    print("The merpeople welcome you to their castle.")
    print("It is beautiful and you get oxygen.")
    print("Now that you have your oxygen, you can either go to the surface or explore Atlantis alone.")
def drowndeath():
    print("You begin to explore around you.")
    print("You avoid the merpeople who avoid you in return.")
    print("But, OH NO, your oxygen begins to run out!")
    print("You run out of air and die.")
def merpeople():
    print("The merpeople talk kindly to you.")
    print("They warn you that your oxygen tank is running low!")
    print("You can follow them to their castle or go back to the surface.")
def alone():
    print("You begin to explore alone and discover a secret caven.")
    print("You go inside and rocks trap you inside!")
    print("You die underwater.")
def famous():
    print("You come back to land with new discoveries!")
    print("Everyone loves you and the two worlds are now connected!")
    print("You win!")
def playGame():
    print("Welcome to Atlantis, the sunken city!")
    time.sleep(1.5)
    print("You are the first adventurer to discover it!")
    time.sleep(1.5)
    print("Do you explore or talk to the merpeople?")
    time.sleep(1.5)
    ans = makeChoice("to explore Atlantis alone", "to talk to the resident merpeople")
    if ans == 1:
        drowndeath()
        askRestart()
    merpeople()
    ans = makeChoice("to go to the castle", "to return to the surface")
    if ans == 2:
        surface()
        askRestart()
    castle()
    ans = makeChoice("to return to the surface", "to explore alone")
    if ans == 1:
        famous()
    else:
        alone()
    askRestart()
playGame()

Answer 2

In general, if you want to be able to 'go back to the beginning' of something, you want to have a loop that contains everything. Like

while True:
    """ game code """

That would basically repeat your entire game over and over. If you want it to end by default, and only restart in certain situations, you would do

while True:
    """ game code """

    if your_restart_condition:
        continue # This will restart the loop

    if your_exit_condition:
        break # This will break the loop, i.e. exit the game and prevent restart

    """ more game code """

    break # This will break the loop if it gets to the end

To make things a little easier, you could make use of exceptions. Raise a RestartException whenever you want to restart the loop, even from within one of your functions. Or raise an ExitException when you want to exit the loop.

class RestartException(Exception):
    pass

class ExitException(Exception):
    pass

while True:
    try:
        """ game code """

    except RestartException:
        continue

    except ExitException:
        break
    break