本文实例讲述了Python面向对象类继承和组合。分享给大家供大家参考,具体如下:

在python3中所有类默认继承object,凡是继承了object的类都成为新式类,以及该子类的子类Python3中所有的类都是新式类,没有集成object类的子类成为经典类(在Python2中没有集成object的类以及它的子类都是经典类

继承式用来创建新的类的一种方式,好处是减少重复代码

class People:
  def __init__(self,name,age):
    self.name=name
    self.age=age
  def walking(self):
    print('%s is walking ' %self.name)
  def talking(self):
    print('%s is talking '%self.name)
class Teacher(People):
  pass
class Student(People):
  pass
t1=Teacher('egon',18)
print(t1.name,t1.age)
t1.walking()
t1.talking()
s1=Student('xiaobai',22)
print(s1.name,s1.age)
s1.talking()
s1.walking()

执行结果

egon 18
egon is walking
egon is talking
xiaobai 22
xiaobai is talking
xiaobai is walking

class People:
  def __init__(self,name,age,sex):
    self.name=name
    self.age=age
    self.sex=sex
  def walking(self):
    print('%s is walking ' %self.name)
  def talking(self):
    print('%s is talking '%self.name)
class Teacher(People):
  def __init__(self,name,age,sex,level,salary):
    People.__init__(name,age,sex)
    self.level=level
    self.salary=salary
  def teaching(self):
    People.talking(self)
    print('%s is teaching'%self.name)
class Student(People):
  def __init__(self,name,age,sex,group):
    People.__init__(name,age,sex)
    self.group=group
  def studying(self):
    People.talking(self)
    print('%s is studying'%self.name)

组合

class Date:
  def __init__(self,year,mon,day):
    self.year=year
    self.mon=mon
    self.day=day
  def tell_birth(self):
    print('出生于<%s>年 <%s>月 <%s>日'%(self.year,self.mon,self.day))
class Teacher:
  def __init__(self,name,age,sex,year,month,day):
    self.name=name
    self.age=age
    self.sex=sex
    self.birth=Date(year,month,day)
  def teaching(self):
    print('%s is teaching'%self.name)
class Student:
  def __init__(self,name,age,sex,year,mon,day):
    self.name=name
    self.age=age
    self.sex=sex
    self.birth=Date(year,mon,day)
  def studying(self):
    print('%s is studying'%self.name)
xiaobai=Student('xiaobai',22,'male','1995','3','16')
xiaobai.birth.tell_birth()

执行结果

出生于<1995>年 <3>月 <16>日

继承和组合

class People:
  def __init__(self,name,age,sex,year,mon,day):
    self.name=name
    self.age=age
    self.sex=sex
    self.birth=Date(year,mon,day)
  def walking(self):
    print('%s is walking ' %self.name)
  def talking(self):
    print('%s is talking '%self.name)
class Date:
  def __init__(self,year,mon,day):
    self.year=year
    self.mon=mon
    self.day=day
  def tell_birth(self):
    print('出生于<%s>年 <%s>月 <%s>日'%(self.year,self.mon,self.day))
class Teacher(People):
  def __init__(self,name,age,sex,level,salary,year,mon,day):
    People.__init__(self,name,age,sex,year,mon,day)
    self.level=level
    self.salary=salary
  def teaching(self):
    People.talking(self)
    print('%s is teaching'%self.name)
class Student(People):
  def __init__(self,name,age,sex,year,mon,day,group):
    People.__init__(self,name,age,sex,year,mon,day)
    self.group=group
  def studying(self):
    People.talking(self)
    print('%s is studying'%self.name)

父类要限制

1、子类必须有父类的方法

2、子类实现的方法必须跟父类的方法的名字一样

import abc
class File(metaclass=abc.ABCMeta):
  @abc.abstractclassmethod
  def read(self):
    pass
  @abc.abstractclassmethod
  def write(self):
    pass

更多关于Python相关内容感兴趣的读者可查看本站专题:《Python面向对象程序设计入门与进阶教程》、《Python数据结构与算法教程》、《Python函数使用技巧总结》、《Python字符串操作技巧汇总》、《Python编码操作技巧总结》及《Python入门与进阶经典教程》

希望本文所述对大家Python程序设计有所帮助。

华山资源网 Design By www.eoogi.com
广告合作:本站广告合作请联系QQ:858582 申请时备注:广告合作(否则不回)
免责声明:本站资源来自互联网收集,仅供用于学习和交流,请遵循相关法律法规,本站一切资源不代表本站立场,如有侵权、后门、不妥请联系本站删除!
华山资源网 Design By www.eoogi.com

RTX 5090要首发 性能要翻倍!三星展示GDDR7显存

三星在GTC上展示了专为下一代游戏GPU设计的GDDR7内存。

首次推出的GDDR7内存模块密度为16GB,每个模块容量为2GB。其速度预设为32 Gbps(PAM3),但也可以降至28 Gbps,以提高产量和初始阶段的整体性能和成本效益。

据三星表示,GDDR7内存的能效将提高20%,同时工作电压仅为1.1V,低于标准的1.2V。通过采用更新的封装材料和优化的电路设计,使得在高速运行时的发热量降低,GDDR7的热阻比GDDR6降低了70%。