PrimePY: using array slicing

[jannekotka]

Changed to use array slicing and numpy. Increases perf
by 20x

Signed-off-by: Janne Kotka lekonna@gmail.com

[jannekotka]

I have also one without numpy. keep the initialization as in the original and replace the for loop with
this.rawbits[int(factor3/2):this.sieveSize//2:factor] = [False] * len(this.rawbits[int(factor3/2):this.sieveSize//2:factor])

[rhbvkleef]

I think that we can consider slicing faithful, but I am open to discussion.

[oscardssmith]

IMO, it might be a good idea to have separate python and python_numpy implementations.

[rbergen]

I would agree that slicing is faithful. However, we can't merge this PR until it is opened on the drag-race branch.

[rbergen]

Closing due to lack of contributor response. Can be reopened on drag-race branch if desired.

[rbergen]

Closing due to lack of contributor response. Can be reopened on drag-race branch if desired.