Not able to plot with ggplot in python

Question

I am trying to get started with the ggplot library in python. I am using V 2.7.6 in Enthought Canopy. When I try to run the simple script

from ggplot import *

print ggplot(mtcars, aes('mpg', 'qsec')) + \
    geom_point(colour='steelblue') + \
    scale_x_continuous(breaks=[10,20,30],  \
                  labels=["horrible", "ok", "awesome"])

I get the following error:

AttributeError: 'DataFrame' object has no attribute 'select_dtypes'

Any ideas? Thanks.