>>> from numpy import *
>>> arr = arange(1, 25, 2)
>>> arr
array([ 1,  3,  5,  7,  9, 11, 13, 15, 17, 19, 21, 23])

>>> arr.reshape(3, 3)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: cannot reshape array of size 12 into shape (3,3)

>>> arr.reshape(3, 4)
array([[ 1,  3,  5,  7],
       [ 9, 11, 13, 15],
       [17, 19, 21, 23]])

>>> reshape(arr, (4, 3))
array([[ 1,  3,  5],
       [ 7,  9, 11],
       [13, 15, 17],
       [19, 21, 23]])
       
>>> arr = arr.reshape(4, 3)
>>> arr
array([[ 1,  3,  5],
       [ 7,  9, 11],
       [13, 15, 17],
       [19, 21, 23]])

>>> arr[1]
array([ 7,  9, 11])

>>> arr[1, 1]
9

>>> arr.ndim
2

>>> shape(arr)
(4, 3)

>>> shape(arr)[0]
4

>>> shape(arr)[1]
3
>>> arr
array([[ 1,  3,  5],
       [ 7,  9, 11],
       [13, 15, 17],
       [19, 21, 23]])

>>> arr[0,:]
array([1, 3, 5])

>>> arr[:,0]
array([ 1,  7, 13, 19])

>>> arr[0:3]
array([[ 1,  3,  5],
       [ 7,  9, 11],
       [13, 15, 17]])

>>> arr[1:4]
array([[ 7,  9, 11],
       [13, 15, 17],
       [19, 21, 23]])

>>> arr[::-1]
array([[19, 21, 23],
       [13, 15, 17],
       [ 7,  9, 11],
       [ 1,  3,  5]])
       
>>> arr = arr.flatten()
>>> arr
array([ 1,  3,  5,  7,  9, 11, 13, 15, 17, 19, 21, 23])

>>> arr.ndim
1
>>> zeros((4, 3), int)
array([[0, 0, 0],
       [0, 0, 0],
       [0, 0, 0],
       [0, 0, 0]])

>>> ones((4, 3), int)
array([[1, 1, 1],
       [1, 1, 1],
       [1, 1, 1],
       [1, 1, 1]])

>>> eye(3)
array([[1., 0., 0.],
       [0., 1., 0.],
       [0., 0., 1.]])