subprogram issues: cannot unpack non-iterable function object error

[buran]

yes, they are defined in the function signature as parameters you expect. However, they are not used in the body of the said function (or at least what you have show us):

correct = 0 
    attempts = 0
    while correct < 4:
        answer1 = False
        while answer1 == False:
            if guess1 == c1: # if answer is correct
                print("Colour in position 1 correct") # print this message 
                correct = correct + 1 # adds 1 to correct total
                attempts = attempts + 1 # adds 1 to attempts total
                answer1 = True # closes while loop
            elif guess1 == c2 or guess1 == c3 or guess1 == c4: # if answer is correct but in wrong place
                print("Colour correct but in wrong place position 1") # prints this message
                attempts = attempts + 1 # adds 1 to attempts total
                guess1 = input("Please enter your choice for the 1st colour: ") # asks user for another guess
            else: # if answer is wrong
                print("Wrong colour chosen") # print this message 
                attempts = attempts + 1 # adds 1 to attempts total
                guess1 = input("Please enter your choice for the 1st colour: ") # asks user for another guess
        answer2 = False # code repeats this process for the other 3 answers 
        while answer2 == False:
            if guess2 == c2:
                print("Colour in position 2 correct")
                correct = correct + 1
                attempts = attempts + 1
                answer2 = True
            elif guess2 == c1 or guess1 == c3 or guess1 == c4:
                print("Colour correct but in wrong place position 2")
                attempts = attempts + 1
                guess2 = input("Please enter your choice for the 2nd colour: ")
            else:
                print("Wrong colour chosen")
                attempts = attempts + 1
                guess2 = input("Please enter your choice for the 2nd colour: ")
        answer3 = False
        while answer3 == False:
            if guess3 == c3:
                print("Colour in position 3 correct")
                correct = correct + 1
                attempts = attempts + 1
                answer3 = True
            elif guess3 == c1 or guess1 == c2 or guess1 == c4:
                print("Colour correct but in wrong place position 3")
                attempts = attempts + 1
                guess3 = input("Please enter your choice for the 3rd colour: ")
            else:
                print("Wrong colour chosen")
                attempts = attempts + 1
                guess3 = input("Please enter your choice for the 3rd colour: ")
        answer4 = False
        while answer4 == False:
            if guess4 == c4:
                print("Colour in position 2 correct")
                correct = correct + 1
                attempts = attempts + 1
                answer4 = True
            elif guess4 == c1 or guess1 == c2 or guess1 == c3:
                print("Colour correct but in wrong place position 4")
                attempts = attempts + 1
                guess2 = input("Please enter your choice for the 4th colour: ")
            else:
                print("Wrong colour chosen")
                attempts = attempts + 1
                guess4 = input("Please enter your choice for the 4th colour: ")
    print("Well done! You got all the colours right") # prints this message when all colours are correct 
    print("The number of guesses taken was: ", attempts) # tells them how many guesses they took 
    data2 = (correct,attempts) # stores these variables as data2 
    return data2 # returns data2 for use in other subprograms 

so, you take 2 arguments and just discard them.