title: Google Compute Engine error installing python pysftp/cryptography package
body: <p>I was trying to install pysftp in my Google Compute Engine VM, but getting the error bellow:</p>
  
  <pre><code>$ sudo pip install pysftp
  ......
  c/_cffi_backend.c:2:20: fatal error: Python.h: No such file or directory
  </code></pre>
  
  <p>or</p>
  
  <pre><code>c/_cffi_backend.c:2:20: fatal error: ffi.h: No such file or directory
  </code></pre>