1.声明⼀个电脑类: 属性:品牌、颜⾊、内存⼤小 方法:打游戏、写代码、看视频
a.创建电脑类的对象，然后通过对象点的方式获取、修改、添加和删除它的属性
b.通过attr相关方法去获取、修改、添加和删除它的属性
class Computer:
__slots__ = ('brand', 'color', 'ram', 'graphics_card', 'cpu')
def __init__(self, brand, color, ram):
self.brand = brand
self.color = color
self.ram = ram
def play_game(self):
pass
def coding(self):
pass
def watch_video(self):
pass
computer1 = Computer('MSI', 'black', '8G')
# a.
brand = computer1.brand # 获取computer1的'brand'属性
computer1.brand = 'Lenovo' # 修改computer1的'brand'属性
computer1.graphics_card = 'GTX765M' # 给computer1添加'graphics_card'属性
del computer1.brand # 删除computer1的'brand'属性
# b.
color = getattr(computer1, 'color') # 获取computer1的'color'属性
setattr(computer1, 'color', 'red') # 修改computer1的'color'属性
setattr(computer1, 'cpu', 'i5-4200M') # 给computer1添加'cpu'属性
delattr(computer1, 'color') # 删除computer1的'color'属性
2.声明⼀个人的类和狗的类:
狗的属性:名字、颜色、年龄
狗的方法:叫唤
人的属性:名字、年龄、狗
人的方法:遛狗
a.创建人的对象小明，让他拥有一条狗大黄，然后让小明去遛大黄
class Human:
def __init__(self, name, age, dog=None):
self.name = name
self.age = age
self.dog = dog
def walking_the_dog(self):
if self.dog:
return '{}正在溜{}'.format(self.name, self.dog.name)
else:
return '你没有狗!'
class Dog:
def __init__(self, name, color, age):
self.name = name
self.color = color
self.age = age
def bark(self):
return '{}:汪汪汪！'.format(self.name)
dog1 = Dog('大黄', '土黄色', 3)
p1 = Human('小明', 18)
p1.dog = dog1
print(p1.walking_the_dog())
3.声明一个圆类，自己确定有哪些属性和方法
class Circle:
def __init__(self, r):
self.r = r
self.pi = 3.1415926
def area(self):
return self.pi*self.r**2
def girth(self):
return 2*self.pi*self.r
4.创建一个学生类:
属性:姓名，年龄，学号
方法:答到，展示学生信息
class Student:
def __init__(self, name, age, study_id):
self.name = name
self.age = age
self.study_id = str(study_id).zfill(3)
def answer(self):
return '{}:到!'.format(self.name)
def info(self):
return 'name:{} age:{} study_id:{}'.format(self.name, self.age, self.study_id)
5.创建一个班级类:
属性:学生，班级名
方法:添加学生，删除学生，点名, 求班上学生的平均年龄
import json
class Class:
def __init__(self, class_name, students):
self.students = students
self.class_name = class_name
def add_student(self, student):
self.students.append(student)
try:
with open('student.json', 'r', encoding='utf-8') as f:
classmates = json.loads(f.read())
except (FileNotFoundError, json.decoder.JSONDecodeError):
with open('student.json', 'w', encoding='utf-8') as f:
f.write(json.dumps({}))
with open('student.json', 'r', encoding='utf-8') as f:
classmates = json.loads(f.read())
classmates[self.class_name] = [student.info() for student in self.students]
with open('student.json', 'w', encoding='utf-8') as f:
f.write(json.dumps(classmates))
def del_student(self, student):
if student in self.students:
self.students.remove(student)
try:
with open('student.json', 'r', encoding='utf-8') as f:
classmates = json.loads(f.read())
except (FileNotFoundError, json.decoder.JSONDecodeError):
with open('student.json', 'w', encoding='utf-8') as f:
f.write(json.dumps({}))
with open('student.json', 'r', encoding='utf-8') as f:
classmates = json.loads(f.read())
classmates[self.class_name] = [student.info() for student in self.students]
with open('student.json', 'w', encoding='utf-8') as f:
f.write(json.dumps(classmates))
else:
return '该学生不存在!'
def call_the_roll(self, student):
if student in self.students:
return student.answer()
def average_age(self):
return sum([student.age for student in self.students])/len(self.students)
student1 = Student('小明', 18, 1)
student2 = Student('小花', 22, 2)
student3 = Student('小红', 20, 3)
class1 = Class('python1904', [student1, student2])
class1.add_student(student3)
print(class1.students)
print(class1.call_the_roll(student1))
print(class1.average_age())
