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)?
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)"