Python Function Pipeline
In this article, we show how to use "Map & Reduce, not loop" to implement function pipeline in python
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| def even_filter(nums): return filter(lambda x: x%2==0, nums)def multiply_by_three(nums): return map(lambda x: x*3, nums)def convert_to_string(nums): return map(lambda x: 'The Number: %s' % x, nums)nums = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]pipeline = convert_to_string( multiply_by_three( even_filter(nums) ) )for num in pipeline: print num |
In the above code, you have to use nested functions to achieve the goal, which is kinda clunky. Actually, a more natural way is as following.
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| pipeline_func(nums, [even_filter, multiply_by_three, convert_to_string]) |
Here is how we implents pipeline_func:
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| def pipeline_func(data, fns): return reduce(lambda a, x: x(a), fns, data) |
