pipeline pattern by python generator

pipeline.py

# -*- coding: utf-8 -*-
import os, sys

def default_next(func):
    def wrapper(*args, **kwargs):
        f = func(*args, **kwargs)
        f.next()
        return f
    return wrapper

@default_next
def finder(target):
    topdir = yield
    for path, dirname, filelist in os.walk(topdir):
        for filename in filelist:
            target.send(os.path.join(path, filename))
 
@default_next
def opener(target):
    while True:
        name = yield
        f = open(name)
        target.send(f)
     
@default_next
def catcher(target):
    while True:
        f = yield
        for line in f:
            target.send(line)
             
@default_next
def printer():
    while True:
        line = yield
        print line
        
        
if __name__ == "__main__":
    pipeliner = finder(opener(catcher(printer())))
    pipeliner.send('/home/fk/test')