title: Why is numpy slower than python? How to make code perform better
body: <p>I revrite my neural net from pure python to numpy, but now it is working even slower. So I tried this two functions:</p>
  
  <pre><code>def d():
      a = [1,2,3,4,5]
      b = [10,20,30,40,50]
      c = [i*j for i,j in zip(a,b)]
      return c
  
  def e():
      a = np.array([1,2,3,4,5])
      b = np.array([10,20,30,40,50])
      c = a*b
      return c
  </code></pre>
  
  <p>timeit d = 1.77135205057</p>
  
  <p>timeit e = 17.2464673758</p>
  
  <p>Numpy is 10times slower. Why is it so and how to use numpy properly? </p>