title: change data type of a array in python
body: <p>I have created a array by generating a group of random numbers and converted them into int type. However, i do not think my way below is efficient. Is there a best way to change the data type in a array?  </p>
  
  <pre><code># standard normal distributed random numbers
  c=random.randn(5,5)
  c
  
  array([[-0.37644781, -0.81347483, -0.36895952, -2.68702544, -0.96780752],
     [ 0.05293328,  1.65260753,  0.55586611, -0.5786392 ,  0.50865003],
     [ 1.25508358,  0.51783276,  2.36435212, -0.23484705, -1.20999296],
     [ 2.07552172,  0.65506648,  0.10231436, -0.26046045,  0.40148111],
     [ 0.24864496, -1.8852587 , -2.51091886,  1.01106003,  1.53118353]])
  
  d=array([[-0.37644781, -0.81347483, -0.36895952, -2.68702544, -0.96780752],
         [ 0.05293328,  1.65260753,  0.55586611, -0.5786392 ,  0.50865003],
         [ 1.25508358,  0.51783276,  2.36435212, -0.23484705, -1.20999296],
         [ 2.07552172,  0.65506648,  0.10231436, -0.26046045,  0.40148111],
         [ 0.24864496, -1.8852587 , -2.51091886,  1.01106003,  1.53118353]],dtype=int)
  
  d
  array([[ 0,  0,  0, -2,  0],
         [ 0,  1,  0,  0,  0],
         [ 1,  0,  2,  0, -1],
         [ 2,  0,  0,  0,  0],
         [ 0, -1, -2,  1,  1]])
  </code></pre>