详解Python中类的定义与使用
时间：2022-03-01 10:18:25|栏目：Python代码|点击： 次
类顾名思义，就是一类事物、或者叫做实例，它用来描述具有共同特征的一类事物。我们在python中声明类的关键词是class，类还有功能和属性，属性就是这类事物的特征，而功能就是它能做什么，也是就是方法或者函数。我们仍然用例子来说明问题。
目标：
1.类的定义
2.父类，子类定义，以及子类调用父类
3.类的组合使用
4.内置功能
1.类的定义
代码如下：
#!/usr/bin/env python
#coding:utf8
class Hotel(object):
"""docstring for Hotel"""
def __init__(self, room, cf=1.0, br=15):
self.room = room
self.cf = cf
self.br = br
def cacl_all(self, days=1):
return (self.room * self.cf + self.br) * days
if __name__ == '__main__':
stdroom = Hotel(200)
big_room = Hotel(230, 0.9)
print stdroom.cacl_all()
print stdroom.cacl_all(2)
print big_room.cacl_all()
print big_room.cacl_all(3)
2.父类、子类以及调用父类
代码如下：
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# 父类
class AddBook(object):
def __init__(self, name, phone):
self.name = name
self.phone = phone
def get_phone(self):
return self.phone
# 子类，继承
class EmplEmail(AddBook):
def __init__(self, nm, ph, email):
# AddBook.__init__(self, nm, ph) # 调用父类方法一
super(EmplEmail, self).__init__(nm, ph) # 调用父类方法二
self.email = email
def get_email(self):
return self.email
# 调用
if __name__ == "__main__":
Detian = AddBook('handetian', '18210413001')
Meng = AddBook('shaomeng', '18210413002')
print Detian.get_phone()
print AddBook.get_phone(Meng)
alice = EmplEmail('alice', '18210418888', 'alice@xkops.com')
print alice.get_email(), alice.get_phone()
3.类的组合使用
代码如下：
#!/usr/bin/env python
# -*- coding: utf-8 -*-
'''
1.class类的组合使用
2.手机、邮箱、QQ等是可以变化的（定义在一起），姓名不可变（单独定义）。
3.在另一个类中引用
'''
class Info(object):
def __init__(self, phone, email, qq):
self.phone = phone
self.email = email
self.qq = qq
def get_phone(self):
return self.phone
def update_phone(self, newphone):
self.phone = newphone
print "手机号更改已更改"
def get_email(self):
return self.email
class AddrBook(object):
'''docstring for AddBook'''
def __init__(self, name, phone, email, qq):
self.name = name
self.info = Info(phone, email, qq)
if __name__ == "__main__":
Detian = AddrBook('handetian', '18210413001', 'detian@xkops.com', '123456')
print Detian.info.get_phone()
Detian.info.update_phone(18210413002)
print Detian.info.get_phone()
print Detian.info.get_email()
4.内置功能(函数（）加与不加的区别）
代码如下：
#!/usr/bin/env python
#coding:utf8
class Books(object):
def __init__(self, title, author):
self.title = title
self.author = author
def __str__(self):
return self.title
def __repr__(self):
return self.title
def __call__(self):
print "%s is written by %s" %(self.title, self.author)
if __name__ == '__main__':
pybook = Books('Core Python', 'Wesley')
print pybook
pybook()
#!/usr/bin/env python
#coding:utf8
class Number(object):
"""Custum object
add/radd -> +;
sub/rsub -> -;
mul/rmul -> *;
div/rdiv -> /;
"""
def __init__(self, number):
self.number = number
def __add__(self, other):
return self.number + other
def __radd__(self, other):
return self.number + other
def __sub__(self, other):
return self.number - other
def __rsub__(self, other):
return other - self.number
def __gt__(self, other):
if self.number > other:
return True
return False
if __name__ == '__main__':
num = Number(10)
print num + 20
print 30 + num
print num - 5
print 11 - num
print num > 20
