title: Plot.ly - Multiple Traces to same Key in Legend
body: <p>I have been using plot.ly and would like to group multiple traces to the same key in the legend.
  I have subplots that show data about a particular user. Id like to have each key represent a user rather than user.data1, user.data2, etc.</p>
  
  <p>Here is an example of what I have now:</p>
  
  <p><a href="https://i.stack.imgur.com/udwRZ.png" rel="noreferrer"><img src="https://i.stack.imgur.com/udwRZ.png" alt=""></a></p>
  
  <p>I would like to group all 1s in to their own key, all 2s to their own key, and all 3s to their own key.</p>
  
  <p>This part of my code demonstrating how I am currently doing the traces</p>
  
  <pre><code>trace1_A = go.Scatter(x=file1.a, y=file1.b, name='1') #plot1
  trace1_B = go.Scatter(x=file1.c, y=file1.d, name='1') #plot2
  trace1_C = go.Scatter(x=file1.e, y=file1.f, name='1') #plot3
  trace1_D = go.Scatter(x=file1.g, y=file1.h, name='1') #plot4
  </code></pre>