import random
import time
correctCount = 0 # Count the number of correct answers
count = 0 # Count the number of questions
NUMBER_OF_QUESTIONS = 5 # Constant
continueLoop = ‘Y’
startTime = time.time() # Get start time
**
while continueLoop == ‘Y’ and count < NUMBER_OF_QUESTIONS:
今天学习中在这里做了一个自己最满意也是最开心的设计。增加了一个and语句，将书里要求的每次输入一个Y来决定是否循环。和原来的5次之后停止循环结合起来。开始的时候我还想着分开两个while来写，但是怎么写的不对。最后灵光一闪。哈哈，在这里加了一个and把5次记数加进去了。
不过还有个小插曲。我加5次记数的时候写成了。NUMBER_OF_QUESTIONS
<5。没有报错。但是只要运行程序就直接提示运行时间为0，次数为了0。后来自己往下看了一眼原来的内容才明白写错了。这个小插曲挺有意思。哈哈，以后研究。谢谢大家欣赏
**
# while count < NUMBER_OF_QUESTIONS:
# Generate two random single-digit integers
number1 = random.randint(0, 9)
number2 = random.randint(0, 9)
# If number1 < number2, swap number1 with number2
if number1 < number2:
number1, number2 = number2, number1
# Prompt the student to answer "What is number1 - number2?"
answer = eval(input("What is " + str(number1) + " - " +
str(number2) + "? "))
# Grade the answer and display the result
if number1 - number2 == answer:
print("You are correct!")
correctCount += 1
else:
print("Your answer is wrong.
", number1, "-",
number2, "is", number1 - number2)
# Increase the count
continueLoop = input("Enter Y to continue and N to quit: ")
count += 1
endTime = time.time() # Get end time
testTime = int(endTime - startTime) # Get test time
print(“Correct count is”, correctCount, “out of”,
NUMBER_OF_QUESTIONS, “
Test time is”, testTime, “seconds”)
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