python：数学测验-数据未存储

Question

My task is to create a quiz for primary school children. The quiz bit works fine. But I must time how long the child takes and store their 'username' 'correctAnswers' and 'timeTaken' into a .txt file for the specific class the child is in. To do that I ask the child their class number and store their information into the file that was specifically made for that class. The problems I in counter are:

The time isnt being rounded even though I have timeTaken = round(etime)in my code

raw_input not being defined (I have no idea how else to define it)

The message "Sorry, we can not save your data as the class you entered is not valid." comes up even when a valid class number has been entered.

Ive searched everywhere but with no luck. Any help at all would be greatly appreciated.

import time
import random
import math

def test():
    num1=random.randint(1, 10)
    num2=random.randint(1, num1)

    ops = ['+','-','*']
    operation = random.choice(ops)

    num3=int(eval(str(num1) + operation + str(num2)))

    print ("What is {} {} {}?".format(num1, operation, num2))
    userAnswer= int(input("Your answer:"))
    if userAnswer != num3:
        print ("Incorrect. The right answer is {}".format(num3))
        return False
    else:
        print("correct")
        return True

username=input("What is your name?")
print ("Welcome {} to the Arithmetic quiz".format(username))
usersClass = input("Which class are you in? (1,2 or 3)")
raw_input("Press Enter to Start...")
start = time.time()
correctAnswers=0
for question_number in range(10):
    if test():
        correctAnswers +=1

print("{}: You got {} answers correct".format(username, correctAnswers))
end = time.time()
etime = end - start
timeTaken = round(etime)
print ("You completed the quiz in {} seconds".format(timeTaken))
if usersClass == 1:
    with open("class1.txt","a+") as f:
        f.write("{}:Scored {} in {} seconds".format(username,correctAnswers,timeTaken))

elif usersClass == 2:
    with open("class2.txt","a+") as f:
        f.write("{}:Scored {} in {} seconds".format(username,correctAnswers,timeTaken))

elif usersClass == 3:
    with open("class3.txt","a+") as f:
        f.write("{}:Scored {} in {} seconds".format(username,correctAnswers,timeTaken))
else:
    print("Sorry, we can not save your data as the class you entered is not valid.")

Answer 1

The return value of input is a str object:

>>> usersClass = input("Which class are you in? (1,2 or 3)")
Which class are you in? (1,2 or 3)3
>>> type(usersClass)
<class 'str'>

As a result, your subsequent checks against int objects will evaluate to False (ie, '3' != 3 ) resulting in what you are seeing.

The conditions of comparing which usersClass the user has selected would need to compare the same type to ensure equality. This means you could convert your return value of input to an int and continue to compare usersClass to an int which would satisfy your comparison as your code is written now,

usersClass = int(input("Which class are you in? (1,2 or 3)"))

or change the conditionals to compare usersClass to the str representation of 1 , 2 and 3 .

if usersClass == '1':
with open("class1.txt","a+") as f:
    f.write("{}:Scored {} in {} seconds".format(username,correctAnswers,timeTaken))
...

As to the problem you are experiencing with raw_input using Python 3, it has been renamed to input : (taken from What's New in Python 3.0 )

PEP 3111: raw_input() was renamed to input(). That is, the new input() function reads a line from sys.stdin and returns it with the trailing newline stripped. It raises EOFError if the input is terminated prematurely. To get the old behavior of input(), use eval(input()).