title: How to import a globally installed package to virtualenv folder
body: <p>So I have a virtualenv folder called venv for my python project.</p>
  
  <p>I can run:</p>
  
  <pre><code>venv/bin/pip install -r requirements.txt
  </code></pre>
  
  <p>Which installs all requirements I need for the project except one, M2Crypto. The only way to install it is through apt-get:</p>
  
  <pre><code>apt-get install python-m2crypto
  </code></pre>
  
  <p>How can I then add this package installed through apt to venv folder?</p>