python的接口实现zope.interface示例

gfrv

python支持多继承，但是不支持接口，zope.inteface是其三方的接口实现库，在twisted中有大量使用

• from zope.interface import Interface
  
  
• from zope.interface import implementer
  
• import socket
  
• 
  
• class IHostNameResolver(Interface):
  
•     def getHostByName(name, timeout = (1, 3, 11, 45)): # 可以不用self
  
•         """
  
  
•         Resolve the domain name C{name} into an IP address.
  
•         """
  
• 
  
• """
  
  
• 类装饰器等价于：implementer(IHostNameResolver)(HostNameResolver)
  
• """
  
• @implementer(IHostNameResolver)
  
• class HostNameResolver:
  
• 
  
•     def getHostByName(self, name, timeout = (1, 3, 11, 45)):
  
•         try:
  
•             address = socket.gethostbyname(name)
  
•         except socket.error:
  
•             return 'none'
  
•         else:
  
•             return address
  
• 
  
• resolver = HostNameResolver()
  
• print resolver.getHostByName('localhost')
  
• 
  
• # 判断HostNameResolver是否实现了接口IHostNameResolver
  
• print IHostNameResolver.implementedBy(HostNameResolver) # True, 调用 SpecificationBasePy.implementedBy()