Alexandre Zani's recipe on function pipelines was useful. I wanted to change it to suit my needs.
Mostly I just wanted to add arbitrary functions and make the pipe line more list like in behavior.
(edit: typos)
Python, 68 lines
Download
Copy to clipboard1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 | class Pipeline(object):
def __init__(self, *args):
if args:
self._func_list=args
else:
self._func_list=[]
def __call__(self, *args, **kwargs):
(fargs,fkwargs) = (args,kwargs)
for f in self:
results = f(*fargs, **fkwargs)
if isinstance(results, tuple) and len(results) == 2 and \
isinstance(results[0],list) and isinstance(results[1],dict):
fargs,kwargs = results
else:
fargs = [results]
fkwargs = {}
return results
def __iter__(self):
for f in self._func_list:
yield f
raise StopIteration
def __eq__(self, other):
return self._func_list == other._func_list
def __add__(self, other):
funcs = other
if callable(other):
funcs = [other]
args = list(self._func_list) + list(funcs)
return Pipeline(*args)
def push(self, f):
return self._func_list.insert(0, f)
def pop(self, *args, **kwargs):
return self._func_list.pop(*args, **kwargs)
def append(self, *args, **kwargs):
return self._func_list.append(*args, **kwargs)
if __name__ == '__main__':
def add_1(x):
return x+1
def mul_2(x):
return (x * 2)
def identity(x):
return x
p = Pipeline(add_1, mul_2, add_1, mul_2, identity)
assert(p(1) == 10)
p = p + mul_2
assert(p(1) == 20)
q = Pipeline(p, add_1, add_1)
assert(q(1) == 22)
r = Pipeline(add_1)
s = Pipeline(add_1)
t = r + s
assert(t(1) == 3)
|
I wanted something that could do the following:
Pipeline(func1, func2) + Pipeline(func3) to work like one would expect.
Or this:
Pipeline(func1, Pipeline(func3, func4), func2)
And I also just wanted regular functions rather than special functions or needing a decorator on the functions I want to use.
Since I'm iterating through the functions, if the Pipeline throws an exception, it's hard to debug.
