TypeError: can only concatenate tuple (not "int") in Python

Question

I'm going to need your help with this constant tuple error I keep getting. Seems that it is a common mathematical error that many have. I have read almost every instance of TypeError including 'not int', 'not list', 'not float' etc. Yet I have failed to figure out why I get it.

I have written the below code that allows you to enter the sum of random number and in the end it calculates your success ratio. So I have a counter "right=right+1" to count my correct answers. Seems as if Python doesn't like that.

Here is what I have written:

import random 
#the main function
def main():
    counter, studentName, averageRight, right, answer, number1, number2 = declareVariables() 
    studentName = inputNames()

    while counter < 10:
        number1, number2 = getNumber()
        answer = getAnswer(number1, number2, answer)
        right = checkAnswer(number1, number2, answer, right)
        counter = counter + 1
    results(right, averageRight)
    displayInfo(studentName, right, averageRight)

def declareVariables():
    counter = 0
    studentName = 'NO NAME'
    averageRight = 0.0
    right = 0.0
    answer = 0.0
    number1 = 0
    number2 = 0
    return counter, studentName, averageRight, right, answer, number1, number2
    
def inputNames():
    studentName = raw_input('Enter Student Name: ')
    return studentName
    
def getNumber():
    number1 = random.randint(1, 500)
    number2 = random.randint(1, 500)
    return number1, number2

def getAnswer(number1, number2, answer):
    print 'What is the answer to the following equation'
    print number1
    print '+'
    print number2
    answer = input('What is the sum: ')
    return answer
    
def checkAnswer(number1, number2, answer, right):
    if answer == number1+number2:
        print 'Right'
        right = right + 1
    else:
        print 'Wrong'
        
    return right, answer
    
def results(right, averageRight):
    averageRight = right/10
    return averageRight
    
    

def displayInfo(studentName, right, averageRight):
    print 'Information for student: ',studentName
    print 'The number right: ',right
    print 'The average right is: ', averageRight
    
# calls main
main()

and I keep getting:

Traceback (most recent call last):
  File "Lab7-4.py", line 70, in <module>
    main()
  File "Lab7-4.py", line 15, in main
    right = checkAnswer(number1, number2, answer, right)
  File "Lab7-4.py", line 52, in checkAnswer
    right = right + 1
TypeError: can only concatenate tuple (not "int") to tuple Press any key to continue . . .

Taima

Answer 1

Your checkAnswer() function returns a tuple:

def checkAnswer(number1, number2, answer, right):
    if answer == number1+number2:
        print 'Right'
        right = right + 1
    else:
        print 'Wrong'

    return right, answer

Here return right, answer returns a tuple of two values. Note that it's the comma that makes that expression a tuple; parenthesis are optional in most contexts.

You assign this return value to right:

right = checkAnswer(number1, number2, answer, right)

making right a tuple here.

Then when you try to add 1 to it again, the error occurs. You don't change answer within the function, so there is no point in returning the value here; remove it from the return statement:

def checkAnswer(number1, number2, answer, right):
    if answer == number1+number2:
        print 'Right'
        right = right + 1
    else:
        print 'Wrong'

    return right

Lukas

Answer 2

right = checkAnswer(number1, number2, answer, right)

You are assigning what is returned by checkAnswer. But you are returning a tuple from it.

return right, answer

So, after the first iteration right becomes a tuple. And when it reaches

right = right + 1

the second time, it fails to add an int to a tuple.

Preclinical

Answer 3

I don't think your averageRight gives the right result. So I fixed the code. I am using IDLE 3.5.2 so some syntax might seem little different (for example print()). So below is the code. You are welcome :)

import random 
#the main function
def main():
    counter, studentName, averageRight, right, answer, number1, number2 = declareVariables() 
    studentName = inputNames()

    while counter < 10:
        number1, number2 = getNumber()
        answer = getAnswer(number1, number2, answer)
        right = checkAnswer(number1, number2, answer, right)
        counter = counter + 1

    A=results(right, averageRight)
    displayInfo(studentName, right, A)

def declareVariables():
    counter = 0
    studentName = 'NO NAME'
    averageRight = 0.0
    right = 0
    answer = 0
    number1 = 0
    number2 = 0
    return counter, studentName, averageRight, right, answer, number1, number2

def inputNames():
    studentName = input('Enter Student Name: ')
    return studentName

def getNumber():
    number1 = random.randint(1, 500)
    number2 = random.randint(1, 500)
    return number1, number2

def getAnswer(number1, number2, answer):
    print ('What is the answer to the following equation')
    print (number1)
    print ('+')
    print (number2)
    answer = int(input('What is the sum: ')) #input would be a int. without adding the int it would make answer a string instead of int. which was reason why it was giving 'wrong' 
    return answer

def checkAnswer(number1, number2, answer, right):
    if answer==number1+number2:
        print ('Right')
        right = right + 1
    else:
        print ('Wrong')

    return right

def results(right, averageRight):
    averageRight = right/10
    return averageRight



def displayInfo(studentName, right, A):
    print ('Information for student: ',studentName)
    print ('The number right: ',right)
    print ('The average right is: ', A)

# calls main
main()

Verminous

Answer 4

Try rightFloat = float(right[0] + 1) and just reference rightFloat. Just a workaround in case you get lazy.

Inextirpable

Did you actually read the OP code? right is meant to be a number throughout, the fact that it becomes a tuple is a surprise, not the goal. – Lukas

Then in that case take the first value of the tuple and add the one to it. Not hard. – Inextirpable

and what about the first call where right is set to 0.0? Instead of fixing the symptom, fix the actual problem. – Lukas

Point taken. But then again You could just do intRight = right[0] + 1 and then just use intRight wherever needed. – Inextirpable

Sorry not int. use a float – Inextirpable

Or a decimal if really necessary. – Inextirpable

But the problem here is that one function returns a tuple because the OP misunderstood some syntax. Fixing that means there is no tuple at all and the problem goes away. – Lukas

Tackling the problem is better than fixing sub-problems it creates. Agreed. Okay, disregard my answer please. Just a workaround if you get lazy. – Inextirpable

Answer 5

I don´t understand were is the problem in this code but all time show "Exception has occurred: TypeError can only concatenate tuple (not "int") to tuple"

C=  (float(10))
F= (float((C * 1,8) + 32),1)
while C<=100:
 print(F)
 C += 10

Vernation

If you have a new question, please ask it by clicking the Ask Question button. Include a link to this question if it helps provide context. - From Review – Wallboard

Answer 6

I got the same error below:

TypeError: can only concatenate tuple (not "int") to tuple

When trying to concatenate tuple type and int type as shown below:

    # tuple # int
print((1, 2) + 3)

So, I changed int type to tuple type as shown below:

print((1, 2) + (3,))

Then, the error above was solved:

(1, 2, 3)

Crews