[Tutor] Implicit passing of argument select functions being called

[Peter Otten]

On 14/07/2022 09:56, Αλέξανδρος Ρόδης wrote:
> I've finally figured ou a solution, I'll leave it here in case it helps
> someone else, using inspect.signature
>
>
> The actuall functions would look like this:
> `
> dfilter = simple_filter(start_col = 6,)
> make_pipeline(
>    load_dataset(fpath="some/path.xlsx",
>    header=[0,1],
>    apply_internal_standard(target_col = "EtD5"),
>   export_to_sql(fname  = "some/name"),
>    ,
>    data _filter = dfilter
>    )

Whatever works ;) I think I would instead ensure that all
transformations have the same signature. functools.partial() could be
helpful to implement this. Simple example:

 >>> def add(items, value):
	return [item + value for item in items]

 >>> def set_value(items, value, predicate):
	return [value if predicate(item) else item for item in items]

 >>> def transform(items, *transformations):
	for trafo in transformations:
		items = trafo(items)
	return items

 >>> from functools import partial
 >>> transform(
	[-3, 7, 5],
         # add 5 to each item
	partial(add, value=5),
         # set items > 10 to 0
	partial(set_value, value=0, predicate=lambda x: x > 10)
)
[2, 0, 10]