title: How to color the area under the curve in Bokeh?
body: <p>I wanted to color the area under the step curve where my x axis is datetime, I've tried the patch but it provides color between the curves and not under the curve. Is there any better way to color the area under the curve?</p>
  
  <p><img src="https://i.stack.imgur.com/mpqSD.png" alt="plot"></p>
  
  <p>Here is the code:</p>
  
  <pre><code>output_file("layout.html")
  df = pd.read_csv( 'file')
  df.day= df.day.apply(lambda x : parser.parse(x))
  s = []
  p_energy_patch = figure(title='graph', plot_width=1000, plot_height=300, x_axis_type="datetime")
  p_energy_patch.step(x = df.day, y = df['total'], line_width=2, color="black", alpha=0.8)
  p_energy_patch.patch(df.day, df['total'], color = "black",alpha=0.5, line_width=2)
  tab2 = Panel(child=p_energy_patch, title="Normal+Patch(WH)")
  tabs = Tabs(tabs=[ tab2])
  s.append(tabs)
  result = column(s)
  show(result)
  </code></pre>