Impossible de convertir de 'int' object de str implicitement

C'est un maths questionnaire composé de questions aléatoires. À la fin du quiz, un score est affiché, puis j'ai essayer de mettre le résultat et le nom de l'étudiant dans un fichier et un message d'erreur apparaît:

import random
import time
counter = 0
#I think the problem is around here?
score = int("0")
count = 0
function = ['+', 'x', '-']
# Introducing quiz
print('Welcome To The Arithmetic Quiz!')
time.sleep(2)
name = input('Please enter you name. ')
time.sleep(1)
print('Thanks', name, '. Let\'s Get Started!')
time.sleep(1)
while counter < 10:
questions.
firstnumber = random.randint(0, 12)
secondnumber = random.randint(0, 6)
operator = random.choice(function)
question = print(firstnumber, operator, secondnumber, '=')
userAnswer = input('Answer:')
if operator == '+':
count = firstnumber + secondnumber
if count == int(userAnswer):
print('Correct!')
score = score+1
else:
print('Incorrect')
elif operator== 'x':
count = firstnumber*secondnumber
if count == int (userAnswer):
print('Correct!')
score = score+1
else:
print('Incorrect')
elif operator== '-':
count = firstnumber - secondnumber
if count == int(userAnswer):
print('Correct!')
score = score + 1
else:
print('Incorrect')
counter += 1
print("Your quiz is over!")
print("You scored", score, "/10")
what_class = input("Please enter your class number: ")
classe = open("what_class.txt", "wt")
type(classe)
classe.write(name + score)
classe.close()

Alors ce message d'erreur s'affiche:

Traceback (most recent call last):
File "C:/4/gcse maths.py", line 61, in <module>
classe.write(name+score)
TypeError: Can't convert 'int' object to str implicitly