title: Plot multiple boxplot in one graph in pandas or matplotlib?
body: <p>I have a two boxplotes </p>
  
  <pre><code>a1=a[['kCH4_sync','week_days']]
  a1.boxplot(by = 'week_days', meanline=True, showmeans=True, showcaps=True, showbox=True,            
                   showfliers=False)
  a2=a[['CH4_sync','week_days']]
  a2.boxplot(by = 'week_days', meanline=True, showmeans=True, showcaps=True, showbox=True,     
                   showfliers=False)
  </code></pre>
  
  <p>But I want to place them in one graph to compare them. Have you any advice to solve this problem? Thanks!</p>