title: ModuleNotFoundError: No module named 'sklearn.tree._criterion'
body: <p>I am able to import sklearn on jupyter notebook. however, when I am trying to import "DecisionTreeClassifier", I am facing "ModuleNotFoundError: No module named 'sklearn.tree._criterion'"  error</p>
  
  <p>Code: </p>
  
  <pre><code>from sklearn.tree import DecisionTreeClassifier
  </code></pre>
  
  <p>Error message:</p>
  
  <pre><code>ModuleNotFoundError                       Traceback (most recent call last)
  &lt;ipython-input-462-f146622b3284&gt; in &lt;module&gt;()
  ----&gt; 1 from sklearn.tree import DecisionTreeClassifier
  
  ~\Anaconda3\lib\site-packages\sklearn\tree\__init__.py in &lt;module&gt;()
        4 """
        5 
  ----&gt; 6 from .tree import DecisionTreeClassifier
        7 from .tree import DecisionTreeRegressor
        8 from .tree import ExtraTreeClassifier
  
  ~\Anaconda3\lib\site-packages\sklearn\tree\tree.py in &lt;module&gt;()
       38 from ..utils.validation import check_is_fitted
       39 
  ---&gt; 40 from ._criterion import Criterion
       41 from ._splitter import Splitter
       42 from ._tree import DepthFirstTreeBuilder
  
  ModuleNotFoundError: No module named 'sklearn.tree._criterion'
  </code></pre>
  
  <p>Any help greatly appreciated!</p>