title: Binpacking -- multiple constraints: weight+volume
body: <p>I have a dataset with 50,000 orders. Each order has ~20 products. Product volume and weight are present (as well as x,y,z dimensions). I have shipping boxes of constant volume V_max and maximum weight capacity of W_max. Per order I want to minimize the number of boxes used under the constraint that V &lt; V_max, and W &lt; W_max. </p>
  
  <p>In searching the web I have come across many binpacking algorithms, but none of them seem to do the trick. Does anyone know of an elegant (and fast) python algorithm for solving this problem? </p>