python数组

import numpy as np
arr1=np.arange(8)
arr2=arr1.reshape(2,4)
print(‘arr1:‘,arr1)
print(‘arr2:‘,arr2)
print(‘arr2[1,2:3]‘,arr2[1,2:3])
print(‘arr2[:,2]‘,arr2[:,2])
print(‘arr2[1][2:3]‘,arr2[1][2:3])
arr=arr2
print(‘Data type:‘,arr.dtype)
print(‘Total number of elements:‘,arr.size)
print(‘Number of dimensions:‘,arr.ndim)
print(‘Shape (dimensionality):‘,arr.shape)
print(‘Memory used (in bytes):‘,arr.nbytes)