title: How to plot a grouped bar chart from multiple datasets
body: <p>I am going through <a href="http://thinkstats.com" rel="nofollow noreferrer">Think Stats</a> and I would like to compare multiple data sets visually. I can see from the book examples that it is possible to generate an interleaved bar graph with a different color for each data set by using a module provided by the book author, how to obtain the same result in <code>pyplot</code>?</p>