<p dir="auto">I get an output like this, why? :</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="E
======================================================================
ERROR: Failure: ImportError (No module named scipy)
----------------------------------------------------------------------
Traceback (most recent call last):
  File &quot;/Library/Python/2.7/site-packages/nose-1.3.0-py2.7.egg/nose/loader.py&quot;, line 402, in loadTestsFromName
    module = resolve_name(addr.module)
  File &quot;/Library/Python/2.7/site-packages/nose-1.3.0-py2.7.egg/nose/util.py&quot;, line 311, in resolve_name
    module = __import__('.'.join(parts_copy))
  File &quot;/Library/Python/2.7/site-packages/sklearn/__init__.py&quot;, line 32, in &lt;module&gt;
    from .base import clone
  File &quot;/Library/Python/2.7/site-packages/sklearn/base.py&quot;, line 10, in &lt;module&gt;
    from scipy import sparse
ImportError: No module named scipy"><pre class="notranslate"><code class="notranslate">E
======================================================================
ERROR: Failure: ImportError (No module named scipy)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Library/Python/2.7/site-packages/nose-1.3.0-py2.7.egg/nose/loader.py", line 402, in loadTestsFromName
    module = resolve_name(addr.module)
  File "/Library/Python/2.7/site-packages/nose-1.3.0-py2.7.egg/nose/util.py", line 311, in resolve_name
    module = __import__('.'.join(parts_copy))
  File "/Library/Python/2.7/site-packages/sklearn/__init__.py", line 32, in &lt;module&gt;
    from .base import clone
  File "/Library/Python/2.7/site-packages/sklearn/base.py", line 10, in &lt;module&gt;
    from scipy import sparse
ImportError: No module named scipy
</code></pre></div>
<hr>
<p dir="auto">Ran 1 test in 0.001s</p>
<p dir="auto">FAILED (errors=1)</p>
<p dir="auto">Not sure if this is properly filed with scikit-learn or pip, but this is what I found. I assumed that pip would install all necessary dependencies upon running</p>
<div class="highlight highlight-source-shell notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="pip install scikit-learn"><pre class="notranslate">pip install scikit-learn</pre></div>
<p dir="auto">However, pip did not install scipy. This lead to a traceback with a very vague error message from the file sklearn/<strong>init</strong>.py,</p>
<div class="highlight highlight-source-python notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="ImportError: cannot import name __check_build"><pre class="notranslate"><span class="pl-v">ImportError</span>: <span class="pl-s1">cannot</span> <span class="pl-s1">import</span> <span class="pl-s1">name</span> <span class="pl-s1">__check_build</span></pre></div>
<p dir="auto">It seems reasonable that scikit-learn would instead alert the user to the fact that there is a missing dependency, and is not actually installed incorrectly.</p>