title: How to get corresponding values in two lists
body: <p>So I have two lists called A and C that each have the same amount of data points stored in them. I have created a new list called E that contains values in C that are greater than 400.</p>
  
  <p>I need to make a plot of E vs. A 
  My question is how do I get the corresponding values that I gained from creating E from the list A so that I can make a plot?</p>
  
  <p>Is there a way to grab the data from A that corresponds with E which might make a new list I could plot? Thanks. </p>
  
  <p>The data I am using is quite a large list, but here is an example:</p>
  
  <pre><code>    xpos,ypos,measurement,error
      96.54, 92.10, 236.69, 23.67
      26.26, 17.36, 457.55, 45.76
      96.15, 52.22, 369.31, 36.93
      53.23, 56.85, 630.77, 63.08
      82.48, 97.64, 198.24, 19.82
  </code></pre>
  
  <p>I have removed the headers and created four lists for each data column: A for the xpos, B for the ypos, C for measurement, and D for error.</p>
  
  <p>C, or measurement is the data set that I edited to be E which has values over 400. I want to get the values from A (xpos) that match up across the row from the values over 400 in C (or measurement).</p>
  
  <p>I am trying to plot in iPython notebook the list I got from E vs. the corresponding values in A. </p>