title: Plotly: How to use multiple datasets with plotly express bar chart?
body: <p>I'm using plotly express and the gapminder dataset to plot a bar chart, to which I have some similar dataset. I found the instructions in their official website and here is the code and figure:</p>
  
  <pre><code>import plotly.express as px
  
  gapminder = px.data.gapminder()
  
  fig = px.bar(gapminder, x="continent", y="pop", color="continent",
    animation_frame="year", animation_group="country", range_y=[0,4000000000])
  fig.show()
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/UNM0N.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/UNM0N.jpg" alt="enter image description here"></a></p>
  
  <p>However, I also wish to add another dataset for each bar as a comparison. Ideally, I wish to have a result as below:
  <a href="https://i.stack.imgur.com/UFvOk.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/UFvOk.jpg" alt="enter image description here"></a></p>
  
  <p>For the result in each bar, I have a dataset as the "total number". 
  For example, for the first bar, the "yellow one" is the total number and "blue one" is the targeted number, just I wish to combine them in the same figure. But the example only shows a single dataset. I wonder how I can change the parameter of "y" to include the two datasets?</p>