Calculation of mode on given data set

mode.py

# sample code to calculate the mode of given data set

from collections import Counter
d_set = [1,3,3,4,5,7,8,9]
def mode(data):
        # return a list might be more than one mode
        c = Counter(data)       # count occurance of the each item 
        max_count = max (c.values())    # find out max value in data
        return [x_i for x_i , count in c.iteritems() if count == max_count ]

mode(d_set)