week4:周测错题

4.如何在类外,给对象动态添加绑定方法

import types
def qingtianzhu(obj,name):
    print("请我叫我一柱擎天,简称{},颜色是{}".format(name,obj.color))
obj.qingtianzhu = types.MethodType(qingtianzhu,obj)
obj.qingtianzhu("擎天柱")

8.菱形继承中,如何查看多继承调用顺序关系

'''mro列表'''

12.写一个能体现多态的案例

class Soldier():
    def attack(self):
        pass

    def back(self):
        pass

# 陆军
class Army(Soldier):
    def attack(self):
        print("[陆军]搏击,ufc,无限制格斗,太极,八卦,占星,制作八卦符")

    def back(self):
        print("[陆军]白天晨跑10公里,也行800百公里")

# 海军
class Navy(Soldier):
    def attack(self):
        print("[海军]潜泳水下30个小时,手捧鱼雷,亲自送到敌人的老挝,炸掉敌人的碉堡")

    def back(self):
        print("[海军]每小时在海底夜行800公里,游的比鲨鱼还快")

# 空军
class AirForce(Soldier):
    def attack(self):
        print("[空军]空中夺导弹,手撕飞机,在空中打飞机,精准弹幕")

    def back(self):
        print("[空军]高中跳伞,落地成盒")

army_obj = Army()
navy_obj = Navy()
af_obj = AirForce()

lst = [army_obj,navy_obj,af_obj] # 对象列表
strvar = """
1.所有兵种开始攻击训练
2.所有兵种开始撤退训练
3.空军练习攻击,其他兵种练习撤退
"""
print(strvar)
num = input("将军请下令,选择训练的种类")
for i in lst:
    if num == "":
        i.attack()
    elif num == "":
        i.back()
    elif num == "":
        if isinstance(i,AirForce):
            i.attack()
        else:
            i.back()
    else:
        print("将军~ 风太大 我听不见~")
        break

19.模拟int强转整型操作,实现相应方法

import math
class MyInt():

    def calc(self,num,sign=1):     

        strvar = num.lstrip("")
        if strvar == "":
            return 0
        return eval(strvar) * sign

    def __call__(self,num):
        if isinstance(num , bool):
            if num  == True:
                return 1
            elif num == False:
                return 0

        elif isinstance(num,int):
            return num

        elif isinstance(num,float):
            # 方法二
            """
            if num >= 0:
                return math.floor(num)
            else:
                return math.ceil(num)
            """
            return math.floor(num) if num >= 0 else  math.ceil(num)

        elif isinstance(num,str):
            if (num[0] == "+" or num[0]== "-") and num[1:].isdecimal():
                if num[0] == "+":
                    sign = 1
                else:
                    sign = -1                    

                return self.calc(num[1:],sign)

            elif num.isdecimal():
                return self.calc(num)
            else:
                return "老铁,这个真转不了"

myint = MyInt()

res = myint(True)
print(res)
res = myint(100)
print(res)
res = myint(3333.14)
print(res, type(res)) 

20.计算类中自定义成员个数

class MyClass():
    pty1 = 1
    pty2 = 2
    __pty3 = 3
    pyt3  =10
    pty100 = 90

    def func1():
        pass

    def __func2():
        pass

    def __func3():
        pass

    def __len__(self):
        lst = []

        dic = MyClass.__dict__ # 遍历类中所有成员
        for i in dic: # 遍历类中所有成员
            if not(i.startswith("__") and i.endswith("__")): # 如果开头和结尾都不是以双下划线结尾
                lst.append(i) # 将符合条件的成员添加到列表中

        return len(lst) 

23.获取当前类继承的父类

'''bases'''