title: Define bubble sizes according to a column and bubble colors according to another column in scatter plot (matplotlib)
body: <p>I'm building a simple scatter plot that reads data from a xls file. 
  It's the classic Life expectancy x GDP per capita scatter plot. Here's the code:</p>
  
  <pre><code>import pandas as pd
  import matplotlib.pyplot as plt
  import matplotlib.cm as cm
  
  #ler a terceira sheet da planilha
  data = pd.read_excel('sample.xls', sheet_name=0)
  data.head()
  
  plt.scatter(x = data['LifeExpec'],
          y = data['GDPperCapita'],
          s = data['PopX1000'],
          c = data['PopX1000'],
          cmap=cm.viridis,
          edgecolors = 'none',
          alpha = 0.7)
  
  for estado in range(len(data['UF'])):
      plt.text(x = data['LifeExpec'][estado],
           y = data['GDPperCapita'][estado],
           s = data['UF'][estado],
           fontsize = 14)
  
  plt.colorbar()
  plt.show()
  </code></pre>
  
  <p>The .xls file:
  <a href="https://i.stack.imgur.com/lBe4C.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/lBe4C.png" alt="enter image description here"></a></p>
  
  <p>The population column from the xls file (PopX1000) is defining the bubbles sizes and currently it's defining their colors as well. 
  I would like the bubbles to change sizes according to population (as they do now), but the colors to change according to the Region the State is in.</p>
  
  <p>I believe I can't simply change the c property because it expects a float value.
  Any tips on how to do this?</p>