We Keep Coding

Do not want to let Computer play his turn once Player enters invalid choice. How to achieve?

I'm a beginner and writing a code for "Rock Paper Scissors" game. I don't want to run this game(code) over and over again, hence, used while loop. Now, at the "else:" step when any invalid choice is typed by the Player, Computer plays it's turn too after which "Invalid choice. Play your turn again!" is displayed.
I want when a Player types any invalid choice, the computer should not play it's turn and we get "Invalid choice. Play your turn again!" displayed, keeping the game running.
Please check my code and point me to the issue. Please explain with the correction. Thanks in advance!
print("Welcome to the famous Rock Paper Scissors Game. \n")
Choices = ["Rock", "Paper", "Scissors"]
while(True):
Player = input("Your turn: ")
Computer = random.choice(Choices)
print(f"Computer's turn: {Computer} \n")
if Player == Computer:
print("That's a tie, try again! \n")
elif Player == "Rock" and Computer == "Scissors":
print("You Won!!! \n")
elif Player == "Rock" and Computer == "Paper":
print("Computer won! \n")
elif Player == "Paper" and Computer == "Scissors":
print("Computer won! \n")
elif Player == "Paper" and Computer == "Rock":
print("You Won!!! \n")
elif Player == "Scissors" and Computer == "Paper":
print("You Won!!! \n")
elif Player == "Scissors" and Computer == "Rock":
print("Computer won! \n")
else:
print("Invalid choice. Play your turn again! \n")

You can check if the input is valid before the computer plays, and ask again if it is invalid using continue -
Choices = ["Rock", "Paper", "Scissors"]
while(True):
Player = input("Your turn: ")
if Player not in Choices: # If it is not in Choices list above
print("Invalid choice. Play your turn again! \n")
continue # This will re run the while loop again.
# If Player gives valid input, then continues this
Computer = random.choice(Choices)
print(f"Computer's turn: {Computer} \n")
# The next lines ....
Also check out - Break, Continue and Pass

I have a bug in my program that I cannot figure out

So, I just recently started coding and decided to make a rock paper scissors game; However, my program has a bug where if the user enters "rock" the correct code block doesn't run. Instead it runs an else statement that's only meant to run when the user enters, "no". I tried using a while loop instead of just if else statements but it didn't make a difference.
import random
q_1 = str(input("Hello, want to play Rock Paper Scissors?:"))
print()
# ^^adds an indent
rpc_list = ["rock", "paper", "scissors"]
comp = random.choice(rpc_list)
# ^^randomly selects r, p, or s
user = str(input("Great, select Rock Paper or Scissors:"))
if q_1 != "yes":
if q_1 == comp:
print("Oh No, a Tie!")
elif q_1 == "rock":
if comp == "paper":
print("I Win!")
else:
print("You Win!")
elif q_1 == "paper":
if comp == "rock":
print("You Win!")
else:
print("I Win!")
else:
if comp == "rock":
print("I Win!")
else:
print("You Win!")
else:
print("Ok :(")

There are a few issues with your code.
First of all your code only plays the game if the user doesn't enter "yes". You need to change if q_1 != "yes": to if q_1 == "yes":.
Secondly, your code asks the user to choose rock, paper or scissors regardless of whether they have said they want to play or not. Fix this by moving user = str(input("Great, select Rock Paper or Scissors:")) to under the if q_1 == "yes": if statement.
Thirdly, your code uses q1 instead of user as it should.
Here is how your code should look:
import random
q_1 = str(input("Hello, want to play Rock Paper Scissors?:"))
print()
# ^^adds an indent
rpc_list = ["rock", "paper", "scissors"]
comp = random.choice(rpc_list)
# ^^randomly selects r, p, or s
if q_1 == "yes":
user = str(input("Great, select Rock Paper or Scissors:"))
if user == comp:
print("Oh No, a Tie!")
elif user == "rock":
if comp == "paper":
print("I Win!")
else:
print("You Win!")
elif user == "paper":
if comp == "rock":
print("You Win!")
else:
print("I Win!")
else:
if comp == "rock":
print("I Win!")
else:
print("You Win!")
print("I played:",comp)
else:
print("Ok :(")

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

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.

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

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()

how to use an if else statement in another while loop

I am new to coding. I want to try writing a simple rock paper scissors game. But I can't figure out how to end the game.
In the end of this program if the user input is wrong I want to go to the end variable again. I tried with the commented lines but its not working.
player1 = input("What is player 1's name ? ")
player2 = input("What is player 2's name ? ")
player1 = player1.title()
player2 = player2.title()
while True:
print(player1 + " What do you choose ? rock / paper / scissors : ")
a = input()
print(player2 + " What do you choose ? rock / paper / scissors : ")
b = input()
if a == "rock" and b == "scissors" :
print(player1, "won !!!")
elif a == "scissors" and b == "rock":
print(player2, "won !!!")
elif a == "paper" and b == "rock":
print(player1, "won !!!")
elif a == "rock" and b == "paper":
print(player2, "won !!!")
elif a == "scissors" and b == "paper":
print(player1, "won !!!")
elif a == "paper" and b == "scissors":
print(player2, "won !!!")
elif a == b:
print("Its a tie :-(")
elif a or b != "rock" or "paper" or "scissors":
print("Wrong input, Try again")
end = input("Do you want to play again ? yes/no ") == "yes"
if input == "yes":
continue
else:
print('''
GAME OVER''')
break
# elif input != "yes" or "no":
# print("Wrong input, Try again. yes or no ?")
I expect it to end game if the input is "no" and restart the game if input is "yes" if the input is not correct I want the prompt to appear again.

Your code has a few issues which need some addressing, and a few places where it can be streamlined. I have made a few changes to your program as well as added a few comments explaining the changes.
player1 = input("What is player 1's name ? ").title() #This uses chaining to streamline code
player2 = input("What is player 2's name ? ").title() #Same as above
while True:
a = input(player1 + " What do you choose ? rock / paper / scissors : ") #no need to use a separate print statement
b = input(player2 + " What do you choose ? rock / paper / scissors : ")
valid_entries = ["rock", "paper", "scissors"] #To check for valid inputs
if (a not in valid_entries) or (b not in valid_entries):
print("Wrong input, try again")
continue
a_number = valid_entries.index(a) #Converting it to numbers for easier comparison
b_number = valid_entries.index(b)
if(a_number == b_number):
print("Its a tie :-(")
else:
a_wins = ((a_number > b_number or (b_number == 2 and a_number == 0)) and not (a_number == 2 and b_number == 0)) #uses some number comparisons to see who wins instead of multiple if/elif checks
if(a_wins):
print(player1, "won !!!")
else:
print(player2, "won !!!")
end = input("Do you want to play again ? yes/no ")
while (end !="yes") and (end != "no"):
print("invalid input, try again")
end = input("Do you want to play again ? yes/no ")
if end == "yes":
continue
else:
print("GAME OVER")
break
These changes also make the check by using another while loop to see if the input to restart the game was valid or not
*Note that I have not tested these changes and some edits may need to be be made

Just check the value of end
if end is True:
continue
else:
break
Since, you have set the value of end as a boolean by comparing the input() to "yes", it will say whether the user wants to end the game?
Also, you are not initializing the input variable, and the last elif condition will always be true as mentioned in the comment.

Well you can simplify your code using a list and then simplify your if tests. You can check the order of the options and based on it make a decision. You can also make the tests standard to minimize the number of if statements. This my suggestion to improve your code. I hope it helps:
# get playe names
player1 = input("What is player 1's name ? ")
player2 = input("What is player 2's name ? ")
player1 = player1.title()
player2 = player2.title()
# init vars
options = ["rock", "paper", "scissors"]
players = [player1, player2]
# start game
while True:
a = input(player1 + " What do you choose ? rock / paper / scissors : ")
b = input(player2 + " What do you choose ? rock / paper / scissors : ")
# check if inputs are correct
while (a not in options or b not in options):
print("Wrong input, Try again")
a = input(player1 + " What do you choose ? rock / paper / scissors : ")
b = input(player2 + " What do you choose ? rock / paper / scissors : ")
# check who won
if abs(options.index(a) - options.index(b)) == 1:
print(players[1*int(options.index(a) > options.index(b))], "won !!!")
elif abs(options.index(b) - options.index(a)) > 1:
print(players[1*int(options.index(a) > options.index(b))], "won !!!")
elif a == b:
print("Its a tie :-(")
# continue or drop game
end = input("Do you want to play again ? yes/no ")
if end == "yes":
continue
else:
print('''
GAME OVER''')
break

Rock, Paper, Scissors - Python

I am trying to complete a rock, paper, scissors assignment for class.
I'm getting a "UnboundLocalError: local variable 'tied' referenced before assignment" error.
Can someone please tell me why I'm getting this error?
import random
user_score = 0
computer_score = 0
tied = 0
def main():
print ("Let's play the game of Rock, Paper, Scissors. ")
while True:
print ("Your current record is", user_score, "wins,", computer_score, "losses and", tied, "ties")
computer_choice = random.randint(1,3)
if computer_choice == 1:
computer_rock()
elif computer_choice == 2:
computer_paper()
else:
computer_scissors()
def computer_rock():
user_choice = input("1 for Rock, 2 for Paper, 3 for Scissors: ")
if user_choice == "1":
print ("Draw! You both chose Rock.")
tied += 1
try_again()
elif user_choice == "2":
print ("You Win! The computer chose Rock, while you picked Paper.")
user_score += 1
try_again()
elif user_choice == "3":
print ("You Lose! You chose scissors, while the computer picked Rock.")
computer_score += 1
try_again()
else:
print ("ERROR: Invalid entry, please re-enter your choice. ")
computer_rock()
def computer_paper():
user_choice = input("1 for Rock, 2 for Paper, 3 for Scissors: ")
if user_choice == "1":
print ("You Lose! You chose rock, while the computer picked Paper.")
computer_score += 1
try_again()
elif user_choice == "2":
print ("Draw! You both picked Paper.")
tied += 1
try_again()
elif user_choice == "3":
print ("You Win! The computer chose Paper, while you picked Scissors.")
user_score += 1
try_again()
else:
print ("ERROR: Invalid entry, please re-enter your choice. ")
computer_paper()
def computer_scissors():
user_choice = input("1 for Rock, 2 for Paper, 3 for Scissors: ")
if user_choice == "1":
print ("You Win! You chose rock, while the computer picked Scissors.")
user_score += 1
try_again()
elif user_choice == "2":
print ("You Lose! The computer chose Scissors, while you picked Paper.")
computer_score += 1
try_again()
elif user_choice == "3":
print ("Draw! You both picked Scissors.")
tied += 1
try_again()
else:
print ("ERROR: Invalid entry, please re-enter your choice. ")
computer_scissors()
def try_again():
choice = input("Play again? Yes or no. ")
if choice == "y" or choice == "Y" or choice == "yes" or choice == "Yes":
main()
elif choice == "n" or choice == "N" or choice == "no" or choice == "No":
print ("Thanks for playing. ")
else:
print ("Try again")
try_again()
main()

Adding the following code as the first line in each of the three computer_() functions should fix your problem.
global tied, user_score, computer_score
There are better ways to accomplish what you're doing, but that should get you over the hump here :)

While Triptych's answer is perfectly acceptable (and also widely used), for a relatively novice-level programmer it is usually better practice to pass arguments into functions instead of utilizing the global keyword.
More info can be found at the Python Documentation: https://docs.python.org/3/tutorial/controlflow.html#defining-functions
In essence, the point is for the programmer to pass what is called an argument (or arguments) into the function, and the function containing those parameters can process this data and return values back to the location where it was called, similar to how the print() function works. You pass a string (ex. "Hi") into the print() function (ex. print("Hi")), and code within this built-in function displays the characters "Hi" onto the screen.
In this case, your code would look something like this:
# In your main function:
def main():
print ("Let's play the game of Rock, Paper, Scissors. ")
while True:
print ("Your current record is", user_score, "wins,", computer_score, "losses and", tied, "ties")
computer_choice = random.randint(1,3)
if computer_choice == 1:
result = computer_rock(user_score, computer_score, tied) ## Notice the difference here
elif computer_choice == 2:
result = computer_paper(user_score, computer_score, tied) ## Those variables you put in the function call are arguments
else:
result = computer_scissors(user_score, computer_score, tied)
# ...
# In the computer_rock() function:
# Even though I only modified this function, you should probably modify all three to suit your needs.
def computer_rock(user_score, computer_score, tied): ## <-- See the parameters?
user_choice = input("1 for Rock, 2 for Paper, 3 for Scissors: ")
if user_choice == "1":
print ("Draw! You both chose Rock.")
tied += 1
try_again()
elif user_choice == "2":
print ("You Win! The computer chose Rock, while you picked Paper.")
user_score += 1
try_again()
elif user_choice == "3":
print ("You Lose! You chose scissors, while the computer picked Rock.")
computer_score += 1
try_again()
return [user_score, computer_score, tied] # Returning a list so it is easier to sort variables
Another thing to note, even though you are calling try_again() to restart the game, it is not a very good idea to call main() inside of a function that will be called by main(). It is better to use a while loop in the main function to regulate and control the flow of the program.
Hopefully this helped!

It caused from a feature in Python.
The following example emits the same Exception. Note that You can't assign to Global-Variable in Local-Scope.
>>> variable = 1
>>> def function():
... variable += 1
...
>>> function()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<stdin>", line 2, in function
UnboundLocalError: local variable 'variable' referenced before assignment
So if you write as the following, the value of Globale-Variable is not changed. This variable in function() is not Global-Variable but Local-Variable. Right?
>>> variable = 1
>>> def function():
... variable = 2
...
>>> function()
>>> variable
1
By the way, this feature is useful for us, because we want to use functions as small as possible, if speaking loudly, simply because we humans don't understand long functions.
Perhaps you want to use the Global-Variable here now, but when you write many and many codes, and can use Global-Variable, you will be panic such as "Where did this variable change?" because there are many places you changed.
If we have codes which we can't know where we change, these codes will be mysterious codes. It's so disgusting.
#Triptych 's answer is also right. If you adopt his answer, this codes will work. However I recommend that you don't use global.
p.s. You can do it in JavaScript.