import pytest from fixtures import data_path from creader import ClusterFileReader, clusterize import sys def test_references_on_clusterize(data_path): fname= (data_path/'beam_En700eV_-40deg_300V_10us_d0_f0_100.clust').as_posix() r = ClusterFileReader(fname) clusters = r.read(10) result = clusterize(clusters) assert sys.getrefcount(clusters) == 2 #Over counts by one due to call by reference assert sys.getrefcount(result) == 2