from time import time import numpy as np import bcolz N = 1e8 dtype = 'i4' t0 = time() a = np.ones(N, dtype=dtype) print("Time numpy.ones() --> %.4f" % (time() - t0)) t0 = time() ac = bcolz.fill(N, dtype=dtype, dflt=1) # ac = bcolz.carray(a) print("Time carray.fill(dflt=1) --> %.4f" % (time() - t0)) print("ac-->", repr(ac)) t0 = time() sa = a.sum() print("Time a.sum() --> %.4f" % (time() - t0)) t0 = time() sac = ac.sum() print("Time ac.sum() --> %.4f" % (time() - t0)) assert (sa == sac)