title: categorical y-axis and datetime x-axis with Bokeh vbar plot
body: <p>I want to draw a vbar plot using bokeh, where x-axis takes datetime and y-axis takes categorical values. </p>
  
  <p>Initially I tried circle plot as follows:</p>
  
  <pre><code>import pandas as pd
  from datetime import datetime
  from dateutil.parser import parse    
  from bokeh.plotting import figure, show, output_notebook    
  from bokeh.models.ranges import FactorRange
  
  x = pd.Series(['2017/1/1', '2017/1/2', '2017/1/3', '2017/1/4']).map(lambda x: parse(x))
  y = ["a", "b", "c", "a"]
  
  p = figure(x_axis_type='datetime', y_range=list(set(y)), plot_width=400, plot_height=200)
  p.circle(x, y, size=10, line_color="blue", line_width=1)
  show(p)
  </code></pre>
  
  <p>It looks good except for the fact that it is not in bar form.</p>
  
  <p><a href="https://i.stack.imgur.com/dpPdZ.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/dpPdZ.jpg" alt="enter image description here"></a></p>
  
  <p>Next, I tried the following code but no plots are displayed:</p>
  
  <pre><code>x = pd.Series(['2017/1/1', '2017/1/2', '2017/1/3', '2017/1/4']).map(lambda x: parse(x))
  y = ["a", "b", "c", "a"]
  
  p = figure(x_axis_type='datetime', y_range=list(set(y)), plot_width=400, plot_height=200)
  p.vbar(x=x, bottom=0, top=y, width=0.1, color="blue")
  
  show(p)
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/gtHvI.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/gtHvI.jpg" alt="enter image description here"></a></p>