title: How to accelerate product of numpy arrays in python
body: <p>I need to product numpy arrays but it's too slow for me. How to fasten it?</p>
  <pre><code>import time
  import numpy as np
  N = 2e6
  a = np.arange(N)
  b = np.arange(N)
  c = np.arange(N)
  d = np.arange(N)
  t1 = time.time()
  e = a*b*c*d
  t1 = time.time() - t1
  print(t1)
  </code></pre>
  <p>I tried to product lists but I don't know how to do it without loops</p>
  <pre><code>list_a = np.array(a).tolist()
  list_b = np.array(b).tolist()
  list_c = np.array(c).tolist()
  list_d = np.array(d).tolist()
  list_e = list_a * list_b * list_b * list_d # Error
  </code></pre>