title: Calculating average of specific rows
body: <p>My code is:</p>
  
  <pre><code>df=pandas.read_csv("data.csv", names=["Date","Team1","Team2","Map","Event"])
  df
  </code></pre>
  
  <p>And the output is: </p>
  
  <pre><code>Date, Team1, Team2, Team1 Score, Team2 Score, Map, Event
  17/3/17, Misfits, Cloud9, 16, 4,overpass, Pro League
  17/3/17, TyLoo, Misfits, 16, 4, cache, Pro League
  17/3/17, Liquid, Misfits, 8, 16, cbble, Proleague
  17/3/17, Misfits, Blight, 16, 7, overpass, Proleague
  17/3/17, Selfless, Misfits, 12, 16, inferno, Proleague
  </code></pre>
  
  <p>My goal is to calculate team "Misfits" score average, which is (16+4+16+16+16)/5=13.6</p>
  
  <p>I know that I can calculate column average by df["Column Name"].mean(), but the problem is that team "Misfits" appears in "Team1" and "Team2" columns.</p>