title: Heatmap with multi-color y-axis and correspondend colorbar
body: <p>I want to create a heatmap with seaborn, similar to <a href="https://stackoverflow.com/questions/47916205/seaborn-heatmap-move-colorbar-on-top-of-the-plot">this</a> (with the following code):</p>
  <pre><code>import matplotlib.pyplot as plt
  import seaborn as sns
  import pandas as pd
  import numpy as np
  
  # Create data
  df = pd.DataFrame(np.random.random((5,5)), columns=[&quot;a&quot;,&quot;b&quot;,&quot;c&quot;,&quot;d&quot;,&quot;e&quot;])
  
  # Default heatmap
  ax = sns.heatmap(df)
  plt.show()
  </code></pre>
  <p>I'd also like to add a new variable (lets say <code>new_var = pd.DataFrame(np.random.random((5,1)), columns=[&quot;new variable&quot;])</code>), such as that the values (and possibly the spine and ticks as well) of the y-axis are colored according to the new variable and a second color bar plotted in the same plot to represent the colors of the y-axis values. How can I do that?</p>