python problem ---> 10 data = mnist.data[sample]-CodePudding

i am new to python. I'm trying to learn how this K NN algorithm works I tried to apply this code.

from sklearn.datasets import fetch_openml
mnist = fetch_openml('mnist_784', version=1)

print (mnist.data.shape)


print (mnist.target.shape)
import numpy as np
sample = np.random.randint(70000, size=5000)
data = mnist.data[sample]
target = mnist.target[sample]
from sklearn.model_selection import train_test_split

xtrain, xtest, ytrain, ytest = train_test_split(data, target, train_size=0.8)

but it does not work it displays an error

(70000, 784)
(70000,)
---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-6-3b6254553355> in <module>
      8 import numpy as np
      9 sample = np.random.randint(70000, size=5000)
---> 10 data = mnist.data[sample]
     11 #target = mnist.target[sample]
     12 #from sklearn.model_selection import train_test_split

~\anaconda3\lib\site-packages\pandas\core\frame.py in __getitem__(self, key)
   3028             if is_iterator(key):
   3029                 key = list(key)
-> 3030             indexer = self.loc._get_listlike_indexer(key, axis=1, raise_missing=True)[1]
   3031 
   3032         # take() does not accept boolean indexers

CodePudding user response：

you are indexing pandas dataframe, and you should use .loc or .iloc, as pointed here, not the normal indexing you are used to with numpy arrays, this should work:

data = mnist.data.loc[sample]
target = mnist.target.loc[sample]