http://stackoverflow.com/questions/10249121/how-to-implement-daisychaining-of-pluggable-function-in-python

daisychain.py

class ProcessingPipeline(object):
    def __init__(self, *functions, **kwargs):
        self.functions = functions
        self.data = kwargs.get('data')

    def __call__(self, data):
        return ProcessingPipeline(*self.functions, data=data)


    def __iter__(self):
        print "iter"
        data = self.data
        for func in self.functions:
            data = func(data)
        return data


class Multiplier(object):

    def __init__(self, by):
        self.by = by

    def __call__(self, data):
        print "call"
        for x in data:
            yield x * self.by

def add(data, y):
    for x in data:
        yield x + y

from functools import partial
by2 = Multiplier(by=2)
sub1 = partial(add, y=-1)
square = lambda data: ( x*x for x in data )

# first operation is square
pp = ProcessingPipeline(square, sub1, by2,)

print list(pp(range(10)))
print list(pp(range(-3, 4)))