title: how to get values in a column corresponding to other values in two columns in pandas?
body: <p>I have 4 columns which are ( "from node", "via node", "to node" , "angle"), I grouped "via node" by maximum "angle", so I got 2 new columns, what I want to do next is to get the corresponding value from "from node" and put it in a column at the new data frame beside "vianode" and "angle"</p>
  
  <p>for example: I should go to the original data frame and check "viaNode" let us say it is (1) , so the maximum angle corresponding  to it is (238), so i have to search using these two values (vianode=1, angle=238) and get the corresponding "fromnode" value, which will be (8) at this example.</p>