title: Numpy: Environment variables affecting import
body: <p>If I reset my environment (as shown below), I am unable to import numpy from python but I can import any other module including wxPython.</p>
  
  <pre><code>import os
  # reset environment
  os.environ = {}
  # Numpy here will fail!
  import numpy
  </code></pre>
  
  <p>import will fail with the following message</p>
  
  <blockquote>
    <p>ImportError: Importing the multiarray numpy extension module failed. 
    Most likely you are trying to import a failed build of numpy. If
    you're working with a numpy git repo, try <code>git clean -xdf</code> (removes
    all files not under version control).  Otherwise reinstall numpy.</p>
    
    <p>Original error was: DLL load failed: The specified module could not be
    found.</p>
  </blockquote>
  
  <p>Does anyone know how to fix this or why it occurs?</p>
  
  <p>p.s. This does not work on windows, but works on linux.</p>
  
  <p>Progress:</p>
  
  <p>Python on windows does not load as its not able to find the libopenblas.dll file. If I do the following, it seems to work</p>
  
  <pre><code>import ctypes
  ctypes.cdll.LoadLibrary(r"C:\python27\lib\site- packages\numpy\.libs\libopenblas.BNVRK7633HSX7YVO2TADGR4A5KEKXJAW.gfortran- win_amd64.dll")
  import numpy
  </code></pre>
  
  <p>However is there a way to set an environment variable so that this is not necessary?</p>
  
  <ol>
  <li><p>Setting os.environ to {} probably does not reset or change the environment, however I am not sure about this.</p></li>
  <li><p>Windows requires the 'SYSTEMROOT': 'C:\Windows' to be set for some reason...</p></li>
  </ol>
  
  <p>once these two requirements are met then the import works</p>