Python with

def pfname(fun):
	def wraper(*args,**kwargs):
		print fun.__name__
		return fun(*args,**kwargs)
	return wraper 

class ContextWith():
	@pfname
	def __enter__(self):
		return self
	@pfname
	def __exit__(self, exc_type, exc_value, exc_traceback):
		pass

	def Helloworld(self):
		print "Hello world"

with ContextWith() as ctx:
	ctx.Helloworld()

__enter__
Hello world
__exit__

Python with

原文：http://blog.csdn.net/tanghuanan/article/details/44099921