This is a Python wrapper of Peter Behroozi's fast3tree
code, which was
(shamlessly) taken from his Rockstar halo finder.
You can install from pypi:
pip install fast3tree
or if you need the latest version:
https://bitbucket.org/yymao/fast3tree/get/master.zip
Here's a minimal example of how you use it in your python code
import numpy as np
from fast3tree import fast3tree
data = np.random.rand(10000, 3)
with fast3tree(data) as tree:
idx = tree.query_radius([0.5, 0.5, 0.5], 0.2)
# do whatever you like with idx