In object-oriented inheritance is a very important feature
Child and parent class, the subclass is the parent class of an extension, for some extensions on the properties and methods of the parent class
Example: did not bring inheritance
# Define a door numbered class and status
class Door(object):
def __init__(self,num,status):
self.num num
self.status = status
def open(self):
self.status = 'open'
def close(self):
self.status = 'close'
# Define a class of the door can be locked
class Lockable(object):
def __init__(self,num,status,locked):
self.num num
self.status = status
self.locked = locked
def open(self):
if not self.locked: # If you do not lock, then I'll open it
self.status = 'open'
else:
print "the door is locked"
def close(self):
self.status = 'close'
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Lockable the above example, we found that this class is the basis of the Door class adds a locked instance variable
And there is no way to lock, the rest is the same.
#inherit
class Door(object):
def __init__(self,num,status):
self.num num
self.status = status
def open(self):
self.status = 'open'
def close(self):
self.status = 'close'
# Inherited from the parent class Door
class Lockable(Door):
def __init__(self,num,status,locked):
super (Lockable, self) .__ init __ (num, status) # here super explain your constructors num inherited your father's class and status two instance variables, the wording of which is fixed (subclass name, self)
self.locked = locked # here because you inherit the parent class, so we will not need to self.num here and self.status assign values to them, locked is new, it needs to assign
# Of the open method overloading
def open(self):
if not self.locked: # If you do not lock, then I'll open it
#调用父类的方法
super(Lockable,self).open()
else:
print "the door is locked"
class Unlockable(Door): #这里我定义了一个没有锁的门，并且我什么都不做，它继承了父类Door，即使他什么都不做，Door的方法它也都继承下来了
pass
u = Unlockable(1,'open')
print (u.status)
l = Lockable(1,'open',True)
l.open()
print (l.status)
l = Lockable(1,'open',False)
l.open()
print (l.status)
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静态方法：
@static_method #静态方法，类的工具包
def info() #不用加self，无需实例化，不能访问实例其他信息
@class_method #类方法，
def info(self): #能访问类变量，不能访问实例变量，不需要实例化，即可调用
@property #将函数变成静态属性，需实例化方可调用，如果不实例化则仅仅是打印内存地址，调用的时候不需要加()
def sayhi(self): #
print "-----say hi",self.name
return "test"
m = MyClass()
print (m.sayhi) #会打印出-----say hi
如果是这样：
print (MyClass.sayhi) #则仅仅只会打印出<property object at 0x0200F8A0>
如果是这样：
print (MyClass.sayhi()) #则会报错
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什么情况需要实例化才能调用，什么情况不需要实例化也能调用：
总结：
你只要看到有self的就代表需要实例化才能调用（仅仅在没有那三个特殊方法的情况下）