设计异常处理类Cexception，并基于异常处理类设计并实现日期类Date

定义一个异常类Cexception解决日期类实现中的自定义异常处理。设计的日期类应包含以下内容：

①  有三个成员数据：年、月、日；

②  有设置日期的成员函数；

③  有用格式"月/日/年"输出日期的成员函数；

④  要求在日期设置及有参构造函数中添加异常处理。

class Cexception :
    def __init__(self,year,month,day):
        if Cexception.judge(year,month,day) :
            self.year = year
            self.month = month
            self.day = day
        else:
            self.year = -1
            self.month = -1
            self.day = -1
            print("日期有误")
    def setTime(self,year,month,day):
        if Cexception.judge(year,month,day) :
            self.year = year
            self.month = month
            self.day = day
        else:
            self.year = -1
            self.month = -1
            self.day = -1
            print("日期有误")
    def display(self):
        if self.month ==-1 or  self.year == -1 or self.day == -1:
            print("",end="")
        else:
            print(str(self.month)+"/"+str(self.day)+"/"+str(self.year))
    def judge(year,month,day):
        leap = False
        legal = False
        if year>0:
            if year % 4 == 0 and year % 100 != 0 or year % 400 == 0:
                leap = True
            if month in [1, 3, 5, 7, 8, 10, 12]:
                if 1 <= day <= 31:
                    legal = True
            elif month in [4, 6, 9, 11]:
                if 1 <= day <= 30:
                    legal = True
            elif month == 2:
                if not leap and 1 <= day <= 28:
                    legal = True
                elif leap and 1 <= day <= 29:
                    legal = True
        else:
            legal = False
        return legal

c = Cexception(-1,8,5)
c.display()
c = Cexception(2018,8,2)
c.display()
c = Cexception(2019,5,29)
c.display()
c = Cexception(2020,5,8)
c.display()