title: Can't Import ColumnTransfomer (Scikit-Learn) - Import Error:Cannot import name 'Parallel'
body: <p>I use the ColumnTransfomer from Scikit-Learn and it usually works fine. Some days its decides to give me this error?</p>
  
  <p>I have updated scikitlearn and it is on version 0.20. I am using Azure Notebooks (Jupyter Notebooks).</p>
  
  <p>Here is the error that printed when I run:</p>
  
  <pre><code>from sklearn.compose import ColumnTransformer
  
  ImportError                               Traceback (most recent call last)
  &lt;ipython-input-71-95a87d70dcfe&gt; in &lt;module&gt;()
  ----&gt; 1 from sklearn.compose import ColumnTransformer
  
  ~/anaconda3_501/lib/python3.6/site-packages/sklearn/compose/__init__.py in &lt;module&gt;()
        6 """
        7 
  ----&gt; 8 from ._column_transformer import ColumnTransformer, make_column_transformer
        9 from ._target import TransformedTargetRegressor
       10 
  
  ~/anaconda3_501/lib/python3.6/site-packages/sklearn/compose/_column_transformer.py in &lt;module&gt;()
       15 
       16 from ..base import clone, TransformerMixin
  ---&gt; 17 from ..utils import Parallel, delayed
       18 from ..externals import six
       19 from ..pipeline import _fit_transform_one, _transform_one, _name_estimators
  
  ImportError: cannot import name 'Parallel'
  </code></pre>
  
  <p>Thanks!</p>
  
  <p>Vrage</p>