9-5.为9-3编写的user类添加一个名为login_attempts的属性,编写一个名为increment_login_attempts()的方法,将属性login_attempts的值加1.
编写一个reset_login_attempts()方法, 将login_attmepts重置为0.
class User2:
def __init__(self, frist_name, last_name, age, login_attempts, **kwargs):
self.frist_name = frist_name
self.last_name = last_name
self.age = age
self.login_attempts = login_attempts
self.dict = {}
for k, v in kwargs.items():
setattr(self, k, v) # setattr(x,y,z)的作用是,将x的属性y赋值z (x.y = z),即 self.k = v 初始化属性并赋值。
self.dict[k] = v
# print(self.dict)
def full_name(self):
full_name = f"{self.last_name} {self.frist_name}".title()
return full_name
def describe_user(self):
print(f"The user-{self.full_name()} is {self.age} years old.")
print(f"{self.full_name()}'s other information:"
f"\n\t{self.dict}")
def greet_user(self):
print(f"Hello , {self.full_name()} !")
def increament_login_attemps(self, increament_attemps):
self.login_attempts += increament_attemps
def reset_login_attemps(self):
self.login_attempts = 0
print(f"The numbr of login attempts reset to {self.login_attempts}.")
user_wang = User2('xihe','wang',7,0)
user_wang.describe_user()
user_wang.increament_login_attemps(4)
print(f"The user's login attemps number is {user_wang.login_attempts} .")
user_wang.reset_login_attemps()
The user-Wang Xihe is 7 years old.
Wang Xihe's other information:
{}
The user's login attemps number is 4 .
The numbr of login attempts reset to 0.
9-6 编写一个名为IceCreamStandRestaurant的类,继承9-1或9-4编写的restaurant类,添加一个flavors属性,用于存储一个由各种冰淇凌组成的列表。
编写一个显示这些列表的方法,创建一个类的实例,并调用这个方法。
class IceCreamStandResraurant(Restaurant):
def __init__(self,restaurant_name,cuisine_type,flavors): #初始化属性时,可以直接增加属性。本例增加了flavors属性
super().__init__(restaurant_name,cuisine_type) #注意:初始化父类的属性时,不可传入self属性,否则报错:传入参数与父类需要参数不一致。
self.flavors = flavors #注意新增加的属性要用self.的形式进行初始化。
def icecream_flavors(self):
print("We serve icecream with the followding flavors:")
for flavor in self.flavors:
print(f"{flavor}\t",end='')
my_icecreamstand = IceCreamStandResraurant('bing dian','icecream',['strawberry','cheese','chocolate','vanilla','cream'])
my_icecreamstand.icecream_flavors()
print('')
We serve icecream with the followding flavors:
strawberry cheese chocolate vanilla cream
The user's name is Wang Yukai .
He/She is 9 years old.
Wang Yukai's other information:
{}
The admin Wang Yukai have following previleges:
Can add post Can del post Can ban user
9-8 创建一个privileges类,它只有一个属性privileges,其中存储admin的权限。将9-7的方法show_previleges移到这个类中。
在admin类中,将一个previleges实例作为其属性。创建一个admin实例,实现show_previleges()功能——显示admin的权限。
class Admin2(User):
def __init__(self,frist_name,last_name,age,**kwargs):
super(Admin2, self).__init__(frist_name,last_name,age,**kwargs)
self.previleges = Previleges()
class Previleges:
def __init__(self,previleges=['Can add post','Can del post','Can ban user']):
self.previleges = previleges
def show_previleges(self):
previleges = self.previleges
print("The admin have the following previleges :")
for previlege in previleges:
print(f"\t{previlege}")
admin_zhang = Admin2('xuesen','zhang',34)
admin_zhang.describe_user()
admin_zhang.previleges.show_previleges()
The user's name is Zhang Xuesen .
He/She is 34 years old.
Zhang Xuesen's other information:
{}
The admin have the following previleges :
Can add post
Can del post
Can ban user
9-9 Motor的子类为ElectricMotor,Battery类被用为ElectricMotor的属性。
给Battery类添加一个名为upgrade_battery()的方法。该方法检查电瓶,如果不是100就升级为100。
创建一个电动摩托的实例,调用get_range(),升级电瓶后,再次调用get_range(),确认是否升级成功。
class Motor: ##首先要输入父类的代码,必须位于子类之前
def __init__(self, make, model, year):
self.make = make
self.model = model
self.year = year
self.odometer_reading = 0
def get_descriptive_name(self):
long_name = f"{self.year} {self.make} {self.model}"
return long_name.title()
def read_odometer(self):
print(f"This boat has {self.odometer_reading} on it.")
def update_odometer(self, miles): ##使用方法修改里程
if miles >= self.odometer_reading: ##如果传入的里程大于原里程
self.odometer_reading = miles ##对里程进行修改
else: # 否则打印警告信息“不准回调里程表”
print("You can't roll the odometer back.")
def increment_odometer(self, miles):
if miles >= 0:
self.odometer_reading += miles
else:
print("You can't roll the odometer back.")
class ElectricMotor(Motor):
def __init__(self, make, model, year):
super().__init__(make, model, year)
self.battery = Battery()
class Battery:
def __init__(self, battery_size=90, motor_model='electric'):
self.battery_size = battery_size
self.motor_model = motor_model
def describe_battery(self):
print(f"The Motor has a {self.battery_size}-kwh battery.")
def get_range(self):
"""打印一条消息,指出点评的续航里程"""
if self.battery_size > 0 and self.motor_model == 'electric':
range = self.battery_size * 0.75
print(f"This motor can go about {range} miles on a full charge.")
if self.battery_size == 0 and self.motor_model != 'electric':
range = int(input("plesas input the tank capacity: ")) * 10
print(f"This motor can go about {range} miles on a full tank.")
def upgrade_battery(self):
if self.battery_size !=100:
self.battery_size = 100
my_electric_motor = ElectricMotor('yadi','M8',2019)
print(f"My electric motor is {my_electric_motor.get_descriptive_name()}.")
my_electric_motor.battery.get_range()
my_electric_motor.battery.upgrade_battery()
my_electric_motor.battery.get_range()
My electric motor is 2019 Yadi M8.
This motor can go about 67.5 miles on a full charge.
This motor can go about 75.0 miles on a full charge.