title: Plot bar graph by grouping numbers
body: <p>I have 'price' column in my data frame ranging from 10 to $1000. I want to group rows by 'price' in range of $100. For example, 1 to 100 in first group, 101 to 200 in second group and so on, and plot a bar graph which shows first bar of first group, second of second group.
  Thank you</p>