小学生四则运算

import random
def LowCalculate():#三年级以下题目，只涉及两个数字的加减运算
    while(True):
        integer1 =random.randint(1, 100)
        integer2 =random.randint(1, 100)
        if (integer1 - integer1>0):
            integer1 = integer1
            integer2 = integer2
        break
    lowsymbol = random.choice("+-")
    if eval(str(integer1)+str(lowsymbol)+str(integer2))>0:
        return str(integer1)+str(lowsymbol)+str(integer2)
def ProperFraction():#产生真分数
    while(True):
        molecular = random.randint(1,100)  #分子
        denominator = random.randint(1,100)  #分母
        if(molecular<denominator):
            return str(molecular)+"/"+str(denominator)
            break
def blacket():#产生三年级以上题目，含真分数的四则运算
    left="("
    right=")"
    integer=str(random.randint(1,100))
    symbol=random.choice("+-*/")
    fraction=ProperFraction()
    if eval(integer+symbol+fraction)>0:
        return left+integer+symbol+fraction+right
def Select():
    if choice == '1':
        k=0
        for i in range (5):
            a = LowCalculate()
            a = str(a)
            b = eval(a)
            print( a ,"=","请输入答案")
            answer = input()
            answer = int(answer)
            if (abs(answer - b)) == 0:
                k=k+1
                print("你的回答正确")
            else:
                print("答案错误", "正确答案是：", b)
        print("你一共答对了", k, "题", "准确率为:", k / 5)
    if choice == '2':
        count=0
        for i in range (5):
            a=blacket()
            b=str(random.choice("+-*/"))
            c=ProperFraction()
            if eval(a+b+c)>0:
                print(a,b,c,"=","    请输入答案:")
            answer = input()
            answer = float(answer)
            if (abs(answer-eval(a+b+c)))<0.1:
                count=count+1
                print("你的回答正确","准确答案是：",eval(a+b+c))
            else:
                print("答案错误","正确答案是：",eval(a+b+c))
        print("你一共答对了",count,"题","准确率为:",count/5)

if __name__ == '__main__':
    print("请选择难度，"
          "三年级以下请输入1",
          "三年级以上请输入2")
    choice = input()
    X=Select()