一、面向对象编程 特征：1、封装 2、继承 3、多态
例子：
>class Book: > count=0 #不要有self，因为count不是依附于某个对象 > def __init__(self,title,price=0.0,author=None): > self.title=title > self.pricep=price > self.author =author > > def __repr__(self) > return'<图书：{}>'.format(self.title) #开发人员用的，用来调试 > def print_info(self): > print(self.title,self.price,self.author) >if __name__=='__main__': > book=Book('Python',price=29.0,author='Tom') > Book.count +=1 > book.print_info() >import datetime >class Student: > def __init__(self,name,birthdate) > self.name=name > self.birthdate=birthdate > def get_age(self): > return datetime.date.today().year-self.birthdate.year >if __name__=='__main__': > s=Student('Tom',datetime.date(1992,3,1)) > print(s.birthdate) > print(s.get.age())三、继承
>class Employee > def __init__(self,department,name,birthdate,salary): > self.department=department > self.name=name > self.birthdate=birthdate > self.salary > def __repr__(self): > return'<员工：{}在工作>'.format(self.name)) >class Programmer(Emloyee): > def __init__(self,department,name,birthdate,salary,specialty,project): > super().