title: ImportError: cannot import name 'MapWrapper'
body: <p>I am trying to use the r2_score() for some curve fits. I have scikit-learn verison 0.19.1 installed, and I have tried:<br />
  <code>from sklearn.metrics import *</code> (or <code>from sklearn.metrics import r2_score()</code>), but it gives me the error:</p>
  <pre><code>ImportError                               Traceback (most recent call last)
  &lt;ipython-input-292-c0154f305c6f&gt; in &lt;module&gt;()
  ----&gt; 1 from sklearn.metrics import *
  
  /anaconda3/lib/python3.6/site-packages/sklearn/metrics/__init__.py in &lt;module&gt;()
        5 
        6 
  ----&gt; 7 from .ranking import auc
        8 from .ranking import average_precision_score
        9 from .ranking import coverage_error
  
  /anaconda3/lib/python3.6/site-packages/sklearn/metrics/ranking.py in &lt;module&gt;()
       24 import numpy as np
       25 from scipy.sparse import csr_matrix
  ---&gt; 26 from scipy.stats import rankdata
       27 
       28 from ..utils import assert_all_finite
  
  /anaconda3/lib/python3.6/site-packages/scipy/stats/__init__.py in &lt;module&gt;()
      386 
      387 &quot;&quot;&quot;
  --&gt; 388 from .stats import *
      389 from .distributions import *
      390 from .morestats import *
  
  /anaconda3/lib/python3.6/site-packages/scipy/stats/stats.py in &lt;module&gt;()
      174 from scipy.spatial.distance import cdist
      175 from scipy.ndimage import measurements
  --&gt; 176 from scipy._lib._util import (_lazywhere, check_random_state, MapWrapper,
      177                               rng_integers, float_factorial)
      178 import scipy.special as special
  
  ImportError: cannot import name 'MapWrapper'
  </code></pre>
  <p>Do you know what that is? Am I still missing something or does it hava to do with some version incompatibilities?
  Same exact thing happens when I try to import lmfit, which I had previously installed.</p>