title: Python2.7 ImportError: cannot import name sigtools
body: <p>I'm running python 2.7.10 on Windows 7 and 8 and receive this message on both machines</p>
  
  <pre><code>Traceback (most recent call last):
    File "&lt;pyshell#9&gt;", line 1, in &lt;module&gt;
      import prefilt
    File "prefilt.py", line 2, in &lt;module&gt;
      from scipy.signal import butter,lfilter
    File "C:\Python27\lib\site-packages\scipy\signal\__init__.py", line 256, in &lt;module&gt;
      from . import sigtools
  ImportError: cannot import name sigtools
  </code></pre>
  
  <p>every time, when i try to import the script, with its first line being </p>
  
  <pre><code>from scipy.signal import lfilter,butter
  </code></pre>
  
  <p>What can it be connected with?</p>