jagmit sandhu wrote: > python newbie. I can't understand the following about numpy arrays: > > x = np.array([[0, 1],[2,3],[4,5],[6,7]]) > x > array([[0, 1], > [2, 3], > [4, 5], > [6, 7]]) > x.shape > (4, 2) > y = x[:,0] > y > array([0, 2, 4, 6]) > y.shape > (4,) > > Why is the shape for y reported as (4,) ? I expected it to be a (4,1) > array. thanks in advance
Why do you expect every array to be a 2D matrix? Why not 3D or 4D? In the shape of y the 4 could be followed by an infinite amount of ones (4, 1, 1, 1, 1, 1,...) Instead numpy uses as many dimensions as you provide: >>> import numpy as np >>> np.array(42).shape () >>> np.array([42]).shape (1,) >>> np.array([[42]]).shape (1, 1) >>> np.array([[[42]]]).shape (1, 1, 1) I think this is a reasonable approach. Dont you? -- https://mail.python.org/mailman/listinfo/python-list
