title: How to combine the usage of operator all and icontains for mongoengine
body: <p>For mongoengine, there are operators <code>all</code> and <code>icontains</code>.  But how can I combine the usage of them?  </p>
  
  <p>Say for each item, I just want to match with <code>icontains</code> but not <code>exact</code>?  I tried to use regex.  I works but unfortunately it would break if I have more than 1 <code>Q</code> in the queryset of mongoengine.  Because it would try to <code>deepcopy</code> the <code>pattern</code> object but unfortunately <code>pattern</code> object can't been copied deeply.</p>