title: For a np.array([1, 2, 3]) why is the shape (3,) instead of (3,1)?
body: <p>I noticed that for a rank 1 array with 3 elements numpy returns (3,) for the shape. I know that this tuple represents the size of the array along each dimension, but why isn't it (3,1)?</p>
  
  <pre><code>import numpy as np
  
  a = np.array([1, 2, 3])  # Create a rank 1 array
  print a.shape            # Prints "(3,)"
  
  b = np.array([[1,2,3],[4,5,6]])   # Create a rank 2 array
  print b.shape                     # Prints "(2, 3)"
  </code></pre>