Mastering pandas - Second Edition

Quartile

A more significant measure of dispersion is the quartile and related interquartile ranges. It also stands for quarterly percentile, which means that it is the value on the measurement scale below which 25, 50, 75, and 100 percent of the scores in the sorted dataset fall. The quartiles are three points that split the dataset into four groups, with each one containing one-fourth of the data. To illustrate this, suppose we have a dataset of 20 test scores that are ranked, as follows:

    In [27]: import random
             random.seed(100)
             testScores = [random.randint(0,100) for p in 
                           xrange(0,20)]
             testScores
    Out[27]: [14, 45, 77, 71, 73, 43, 80, 53, 8, 46, 4, 94, 95, 33, 31, 77, 20, 18, 19, 35]
    
    In [28]: #data needs to be sorted for quartiles sortedScores ...