Zip type hinting and starmap

[Drvanon]

For whatever reason, pylance does not recongnize zip as a method on the Chain object.

Cannot access member "zip" for type "Chain[list[Hit]]"

This means that type hinting for chains using zip completely fails.

Besides that, the workflow with zip is also very uncomfortable. For example in the following piece of code.

plates = ["barcode1", "barcode 2"]
wells = [f"{row}{column} for row in "abcdefgh" for column in range(1, 13)]
hits = [("barcode3", "a4"), ("barcode3", "g5"), ("barcode4", "d2")]
movements = (
    py_(itertools.product(plates, wells))
    .zip(hits)
    .map(lambda tup: (tup[0][0], tup[0][1], tup[1][0], tup[1][1]))
    .value()
)

I would suggest a starmap method on chain that unpacks tuples to an iteratee.

movements = (
    py_(itertools.product(plates, wells))
    .zip(hits)
    .starmap(lambda source, destination: (source[0], source[1], destination[0], destination[1]))
    .value()
)

The starmap method could look something like:

def starmap(f: Func[[A, K], R], *args: A, **kwargs: K) -> R:
    return  f(*args, **kwargs)

class Chain:
    ...
    def starmap(self, f: Func[[?], R] -> Chain[R]):
        return wrap(f(self._value))
    ...

[dgilland]

Are you seeing the same issue when you use pydash.zip_ directly with the same arguments that would be passed to the chained method call? Wondering if the typing issue is in the zip function and the chain zip method or just the chain method. FYI @DeviousStoat

For starmap, you can do do that using map and spread:

movements = (
    py_(itertools.product(plates, wells))
    .zip(hits)
    .map(py_.spread(lambda source, destination: (source[0], source[1], destination[0], destination[1])))
    .value()
)

[DeviousStoat]

There was a problem with the type stub generator script, it was skipping the functions with only vararg. So zip was not included along with some other functions.
#203 This should fix it

[dgilland]

Fix for this has been released: https://pypi.org/project/pydash/7.0.6/