Outer Product

Open
#43 4 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
35/100
Issue type
Feature
Clarity
Mostly clear
Activity status
Stale
Tech stack
python
Domain
data, stream-processing

Research direction

Start from the Stream and product usage shown in the issue, then inspect the stream operator implementation and existing tests for related combinators. Determine how the outer product should behave as values arrive and how completion is represented; done means the paired example produces the nine multiplication results without an unresolved memory strategy.

Written by the indexing model from the issue text.

Description

Here is my attempt at an example:

from streams import Streams
from operator import mul
s1 = Stream()
s2 = Stream()

op = s1.product(s2, mul)
L = op.sink_to_list()
a = [1, 2, 3]
b = [4, 5, 6]

for x, y in zip(a, b):
    s1.emit(x)
    s2.emit(y)
print(L)

[4, 5, 6, 8, 10, 12, 12, 15, 18]

The best way that I can kind of come up with this is to stash all but one of the streams into a list and then for each incoming piece of data perform an itertools.product on the resulting iterable and push it into some function. I'm not so crazy about this as it means we end up storing a bunch of stuff in memory which seems un-stream like.

Dominant language
Python
Stars
1.3k
Forks
149
No merged PRs in 30d

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from python-streamz/streamz

All issues in python-streamz/streamz

Similar issues

More Python issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.