title: unable to understand the output of the commands in np.arange
body: <pre><code>i=np.arange(0,2.1,0.5,dtype='int8')
  print(i)
  [0 0 0 0 0]
  
  
  g=np.arange(0.5,2.1,0.5,dtype='int8')
  print(g)
  [0 1 2 3]
  
  
  n=np.arange(257,260,0.5,dtype='int16')
  print(n)
  [257 257 257 257 257 257]
  
  p=np.arange(257,260,0.5,dtype='int8')
  print(p)
  [1 1 1 1 1 1]
  
  
  o=np.arange(257.5,260,0.5,dtype='int16')
  print(o)
  [257 258 259 260 261]
  
  q=np.arange(257.5,260,0.5,dtype='int8')
  print(q)
  [1 2 3 4 5]
  </code></pre>