To continue our investigation of this dataset, we are going to examine the makes and models of the various automobiles more closely, repeating many of the steps from the previous chapter while translating from R to Python.
If you've completed the previous recipe, you should have everything you need in order to continue.
The following steps will lead us through our investigation:
- Let's look at how makes and models of cars inform us about fuel efficiency over time. First, let's look at the frequency of makes and models of cars available in the U.S., concentrating on 4-cylinder cars. To select the 4-cylinder cars, we first make the
cylindersvariable unique to see what the possible values are:
In [30]: pd.unique(vehicles_non_hybrid.cylinders)
...:
Out[30]: array([ 4., 12., 8., 6., 5., 10., 2., 3., 16., nan])Both 4.0 and 4 are listed as unique values; this fact should raise your suspicion. Remember,...