Python’s sum vs. NumPy’s numpy.sum

by

I got curious and timed it. numpy.sum seems much faster for numpy arrays, but much slower on lists.

import numpy as np
import timeit

x = range(1000)
# or 
#x = np.random.standard_normal(1000)

def pure_sum():
    return sum(x)

def numpy_sum():
    return np.sum(x)

n = 10000

t1 = timeit.timeit(pure_sum, number = n)
print 'Pure Python Sum:', t1
t2 = timeit.timeit(numpy_sum, number = n)
print 'Numpy Sum:', t2

Result when x = range(1000):

Pure Python Sum: 0.445913167735
Numpy Sum: 8.54926219673

Result when x = np.random.standard_normal(1000):

Pure Python Sum: 12.1442425643
Numpy Sum: 0.303303771848

I am using Python 2.7.2 and Numpy 1.6.1

More Related Contents:

  1. Why is “1000000000000000 in range(1000000000000001)” so fast in Python 3?
  2. How do you fix “runtimeError: package fails to pass a sanity check” for numpy and pandas?
  3. Rolling window for 1D arrays in Numpy?
  4. Roll rows of a matrix independently
  5. Conditionally fill column values based on another columns value in pandas
  6. Link ATLAS/MKL to an installed Numpy
  7. Bin elements per row – Vectorized 2D Bincount for NumPy
  8. Fastest way to grow a numpy numeric array
  9. Vectorized searchsorted numpy
  10. Why “numpy.any” has no short-circuit mechanism?
  11. numpy is already installed with Anaconda but I get an ImportError (DLL load failed: The specified module could not be found)
  12. Vectorizing Haversine distance calculation in Python
  13. Why is numpy.array so slow?
  14. scipy curve_fit doesn’t like math module
  15. Efficient evaluation of a function at every cell of a NumPy array
  16. why isn’t numpy.mean multithreaded?
  17. Why is `np.sum(range(N))` very slow?
  18. Why is a `for` over a Python list faster than over a Numpy array?
  19. Performance: Matlab vs Python
  20. Are NumPy’s math functions faster than Python’s?
  21. time.time vs. timeit.timeit
  22. Efficiently replace elements in array based on dictionary – NumPy / Python
  23. Python pandas: how to remove nan and -inf values
  24. What are the differences between bool() and operator.truth()?
  25. Loading text file containing both float and string using numpy.loadtxt
  26. In sklearn.decomposition.PCA, why are components_ negative?
  27. Creating a numpy array of 3D coordinates from three 1D arrays
  28. Split Python sequence (time series/array) into subsequences with overlap
  29. numpy faster than numba and cython , how to improve numba code
  30. Is this the best way to add an extra dimension to a numpy array in one line of code?

Leave a Comment