14.7 Cats by gender in each locality

Our goal in this section is to create and plot a DataFrame containing the number of female and male cats per locality. We begin with a version of building the DataFrame via comprehensions.

The unique function returns a numpy array of the unique values in a pandas column.

localities = df["Locality"].unique()
localities

array(['DANDENONG NORTH', 'DANDENONG', 'SPRINGVALE', 'SPRINGVALE SOUTH',
       'KEYSBOROUGH', 'NOBLE PARK NORTH', 'NOBLE PARK', 'BANGHOLME',
       'DANDENONG SOUTH', 'LYNDHURST'], dtype=object)

type(localities)

numpy.ndarray

To make it easier for users to understand the results, we put the localities in alphabetical order. The numpy sort method sorts an array in place.

localities.sort()
localities

array(['BANGHOLME...