On: Making Python faster with Rust

[biomcgary]

The slowness comes from the interaction of numpy and a Python object "Polygon", which in not numpy. I suspect that a sufficiently clever coder could have optimized the result without resorting to Rust, but at the cost of a substantial increase in complexity of the codebase. The proposed approach keep the Python code simple (and moves the complexity into having another language to deal with).

[alex_smart → biomcgary]

    diff --git a/poly_match_v1.py b/poly_match_v1.py
    index 675c88a..4293a46 100644
    --- a/poly_match_v1.py
    +++ b/poly_match_v1.py
    @@ -1,4 +1,5 @@
     from functools import cached_property
    +from itertools import compress
     from typing import List, Tuple
     import numpy as np
     from dataclasses import dataclass
    @@ -56,11 +57,8 @@ def generate_example() -> Tuple[List[Polygon], List[np.array]]:
     def find_close_polygons(
  polygon_subset: List[Polygon], point: np.array, max_dist: float
     ) -> List[Polygon]:
    -    close_polygons = []
    -    for poly in polygon_subset:
    -        if np.linalg.norm(poly.center - point) < max_dist:
    -            close_polygons.append(poly)
    -
    +    dist = np.linalg.norm([poly.center for poly in polygon_subset] - point, axis=1)
    +    close_polygons = list(compress(polygon_subset, dist < max_dist))
  return close_polygons

10x faster than the original, without resorting to native code, and without substantial increase in complexity of code base.

[mgraupner → alex_smart]

I wish the author would take your suggestion (and other recommendations) here and try it out again. Would be a very interesting follow up to read: "How we speed up Python and simplifying our codebase by removing on more dependency".

[nossid → mgraupner]

Focusing on speeding up find_close_polygons instead of realizing that you're matching many points against the same set of polygons is also unfortunate, since that function being slow is a red herring. You can create a scipy.spatial.KDTree for example and just query all the points against that.