吴裕雄--天生自然Numpy库学习笔记：NumPy 高级索引

import numpy as np 

x = np.array([[1,  2],  [3,  4],  [5,  6]])

y = x[[0,1,2],  [0,1,0]]

print (y)

import numpy as np 

x = np.array([[  0,  1,  2],[  3,  4,  5],[  6,  7,  8],[  9,  10,  11]])

print ('我们的数组是：' )

print (x)

print ('\n')

rows = np.array([[0,0],[3,3]])

cols = np.array([[0,2],[0,2]])

y = x[rows,cols]

print  ('这个数组的四个角元素是：')

print (y)

import numpy as np

a = np.array([[1,2,3], [4,5,6],[7,8,9]])

b = a[1:3, 1:3]

c = a[1:3,[1,2]]

d = a[...,1:]

print(b)

print(c)

print(d)

import numpy as np 

x = np.array([[  0,  1,  2],[  3,  4,  5],[  6,  7,  8],[  9,  10,  11]])

print ('我们的数组是：')

print (x)

print ('\n')

# 现在我们会打印出大于 5 的元素

print  ('大于 5 的元素是：')

print (x[x >  5])

import numpy as np 

a = np.array([np.nan,  1,2,np.nan,3,4,5])

print (a[~np.isnan(a)])

import numpy as np 

a = np.array([1,  2+6j,  5,  3.5+5j])

print (a[np.iscomplex(a)])

import numpy as np 

x=np.arange(32).reshape((8,4))

print (x[[4,2,1,7]])

x=np.arange(32).reshape((8,4))

print (x[[-4,-2,-1,-7]])

import numpy as np 

x=np.arange(32).reshape((8,4))

print (x[np.ix_([1,5,7,2],[0,3,1,2])])