title: Can we sort the x axis in a Python plot after plotting it?
body: <p>I am trying to plot two columns from two different dataframes in one graph. 
  I have figured out the code to plot it in one but the x axis needs to be in ascending order. Can we do that in this case?</p>
  
  <pre><code>df1=pd.DataFrame({ 'ID': ['A1','A2','A6','A7','A9'], 'F1_S': [23,75,42,77,54] },
                   columns=['ID', 'F1_S'])
  df2=pd.DataFrame({ 'ID': ['A3','A4','A5','A8'], 'F1_S': [66,43,56,86] },
                   columns=['ID', 'F1_S'])
  x1 = list(df1['ID'])
  y1= list(df1['F1_S'])
  lists1 = sorted(zip(*[x, y1]))
  x1, y1 = zip(*sorted(zip(x1, y1)))
  
  x2 = list(df2['ID'])
  y2= list(df2['F1_S'])
  lists2 = sorted(zip(*[x2, y2]))
  x2, y2 = zip(*sorted(zip(x2, y2)))
  
  plt.plot (x1,y1)
  plt.plot(x2,y2)
  </code></pre>