Size-biased Extinction 2 (Scientific)

This is a follow up to Size-biased Extinction 1.

Looking at the average mass of extinct and extant species overall is useful, but there are lots of different processes that could cause size-biased extinctions so it’s not as informative as we might like. However, if we see the exact same pattern on each of the different continents that might really tell us something. Repeat the analysis in the Numpy 1 problem, but this time compare the mean masses within each of the different continents. Export your results to a csv file where the first entry on each line is the continent, the second entry is the average mass of the extant species on that continent, the third entry is the average mass of the extinct species on that continent, and the forth entry is the difference between the average extant and average extinct masses. Use you handy export_to_csv() function:

def export_to_csv(data, filename):
    """Export list of lists to comma delimited text file"""
    outputfile = open(filename, 'wb')
    datawriter = csv.writer(outputfile)
    datawriter.writerows(data)
    outputfile.close()

Call the file continent_mass_differences.csv. If you notice anything strange think about what’s going on and present the final data in the way that makes the most sense to you.

Expected outputs for Size-biased Extinction 2: