title: How can I put different legends to subplots in plotly?
body: <p>I am still designing what kind of plot with subplots I want to do but when we see the example in the <a href="https://plotly.com/python/subplots/" rel="nofollow noreferrer">documentation</a> <em>Multiple Subplots with Titles</em> we have</p>
  <pre><code>from plotly.subplots import make_subplots
  import plotly.graph_objects as go
  
  fig = make_subplots(
      rows=2, cols=2,
      subplot_titles=(&quot;Plot 1&quot;, &quot;Plot 2&quot;, &quot;Plot 3&quot;, &quot;Plot 4&quot;))
  
  fig.add_trace(go.Scatter(x=[1, 2, 3], y=[4, 5, 6]),
                row=1, col=1)
  
  fig.add_trace(go.Scatter(x=[20, 30, 40], y=[50, 60, 70]),
                row=1, col=2)
  
  fig.add_trace(go.Scatter(x=[300, 400, 500], y=[600, 700, 800]),
                row=2, col=1)
  
  fig.add_trace(go.Scatter(x=[4000, 5000, 6000], y=[7000, 8000, 9000]),
                row=2, col=2)
  
  fig.update_layout(height=500, width=700,
                    title_text=&quot;Multiple Subplots with Titles&quot;)
  
  fig.show()
  </code></pre>
  <p>which gives</p>
  <p><a href="https://i.stack.imgur.com/tmvMJ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/tmvMJ.png" alt="plot with subplots" /></a></p>
  <p>which is fine but notice that there is only <em>one</em> place for the legends.(trace 0, trace 1.etc)</p>
  <p>In my design the upper left plot has one legend and the other three share some other legend . Is there a way to individualize or customize the legends of subplots?</p>