title: ImportError: /usr/local/lib/python2.7/lib-dynload/_io.so: undefined symbol: _PyCodec_LookupTextEncoding
body: <p>When I used command : <code>pip freeze</code> it shows message error follow: </p>
  
  <pre><code>Traceback (most recent call last):
   File "/usr/local/bin/pip", line 7, in &lt;module&gt;
    from pip import main
    File "/usr/local/lib/python2.7/site-packages/pip/__init__.py", line in &lt;module&gt;
    from pip.utils import get_installed_distributions, get_prog
   File "/usr/local/lib/python2.7/site-packages/pip/utils/__init__.py", line 6, in &lt;module&gt;
   import io
   File "/usr/local/lib/python2.7/io.py", line 51, in &lt;module&gt;
   import _io
   ImportError: /usr/local/lib/python2.7/lib-dynload/_io.so: undefined symbol: _PyCodec_LookupTextEncoding
  </code></pre>
  
  <p>which pip:</p>
  
  <pre><code>/usr/local/bin/pip
  </code></pre>
  
  <p>which python:</p>
  
  <pre><code>/usr/local/bin/python
  </code></pre>
  
  <p>I do not know why it's in error ! so I hope anybody can help me to resolve problem ! thank you.</p>