module 'cv2' has no attribute 'KNearest_create'

python版本：3.6.5

opencv版本：3.2.0

使用的是jupyter notebook

源代码如下：

import cv2
import numpy as np
import matplotlib.pyplot as plt

%matplotlib inline

# Feature set containing (x,y) values of 25 known/training data
trainData = np.random.randint(0,100,(25,2)).astype(np.float32)

# Labels each one either Red or Blue with numbers 0 and 1
responses = np.random.randint(0,2,(25,1)).astype(np.float32)

# Take Red families and plot them
red = trainData[responses.ravel()==0]
plt.scatter(red[:,0],red[:,1],80,'r','^')

# Take Blue families and plot them
blue = trainData[responses.ravel()==1]
plt.scatter(blue[:,0],blue[:,1],80,'b','s')

# plt.show()

newcomer = np.random.randint(0,100,(1,2)).astype(np.float32)
plt.scatter(newcomer[:,0],newcomer[:,1],80,'g','o')

knn = cv2.KNearest_create()

knn.train(trainData,cv2.ml.ROW_SAMPLE,responses)
ret, results, neighbours ,dist = knn.findNearest(newcomer, 3)

print ("result: ", results,"\n")
print ("neighbours: ", neighbours,"\n")
print ("distance: ", dist)

plt.show()

出现的错误：

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-18-35bac89cb177> in <module>()
     18 plt.scatter(newcomer[:,0],newcomer[:,1],80,'g','o')
     19
---> 20 knn = cv2.KNearest_create()
     21
     22 knn.train(trainData,cv2.ml.ROW_SAMPLE,responses)

AttributeError: module 'cv2' has no attribute 'KNearest_create'

解决方法：

opencv官方教程中的是opencv2的版本

在3中需要使用

cv2.ml.KNearest_create()

参考链接：https://stackoverflow.com/questions/34247502/cv2-ml-knearest-object-has-no-attribute-find-nearest