title: Pandas table lookup
body: <p>I have a pandas lookup table which looks like this</p>
  
  <pre><code>Grade   Lower_Boundary  Upper_Boundary
  1   -110    -96
  2   -96 -91
  3   -91 -85
  4   -85 -81
  5   -81 -77
  6   -77 -72
  7   -72 -68
  8   -68 -63
  9   -63 -58
  10  -58 -54
  11  -54 -50
  12  -50 -46
  13  -46 -42
  14  -42 -38
  15  -38 -34
  16  -34 -28
  17  -28 -18
  18  -18 -11
  19  -11 -11
  20  -11 -9
  </code></pre>
  
  <p>I have another pandas dataframe that looks contains score. I want to assign 'Grade' to the score column, by looking up the look up table. So based on which interval of lower and upper boundary the score falls, the grade should be assigned from that row in the lookup table. Is there a way to do it without typing a bunch of if then else statements? I am thinking just of excel's index match.</p>
  
  <pre><code>Score   Grade
  -75 6
  -75 6
  -60 9
  -66 8
  -66 8
  -98 1
  -60 9
  -82 4
  -70 7
  -60 9
  -60 9
  -60 9
  -56 10
  -70 7
  -70 7
  -70 7
  -66 8
  -56 10
  -66 8
  -66 8
  </code></pre>