Finding frequency distribution of a list of numbers in python

mk_sch picture mk_sch · Nov 11, 2016 · Viewed 8.7k times · Source

I have a Long list of numbers like the following. I would like to find frequency distribution of each number, but I could not use Counter function to get frequency of each item, as they are integers and I get the error that it is not iterable , and therefore I could not convert the list to strings. I checked the similar questions but they did not work for me.

data=[1.0, 2.0, 1.0, 1.0, 1.0, 0.0, 0.0, 0.0, 15.0, 0.0, 0.0, 0.0, 0.0, 3.0, 1.0, 1.0, 1.0, 0.0, 0.0, 1.0, 7.0, 1.0, 0.0, 0.0, 4.0, 3.0, 3.0, 1.0, 1.0, 2.0, 4.0, 0.0, 1.0, 7.0, 2.0, 1.0, 1.0, 4.0, 1.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0, 1.0, 2.0, 3.0, 2.0, 1.0, 1.0, 0.0, 1.0, 1.0, 1.0, 0.0, 10.0, 0.0, 1.0, 1.0, 0.0, 0.0, 1.0, 2.0, 3.0, 0.0, 3.0, 2.0, 11.0, 0.0, 5.0, 2.0, 0.0, 1.0, 2.0, 1.0, 8.0, 1.0, 0.0, 6.0, 2.0, 4.0, 0.0, 17.0, 0.0, 27.0, 2.0, 2.0, 1.0, 1.0, 3.0, 2.0, 0.0, 0.0, 6.0, 0.0, 0.0, 1.0, 1.0, 2.0, 0.0, 10.0, 0.0, 0.0, 5.0, 7.0, 1.0, 0.0, 1.0, 2.0, 1.0, 5.0, 2.0, 1.0, 9.0, 1.0, 0.0, 2.0, 0.0, 1.0, 3.0, 1.0, 1.0, 0.0, 0.0, 3.0, 5.0, 2.0, 0.0, 1.0, 9.0, 0.0, 0.0, 1.0, 1.0, 0.0, 0.0, 1.0, 1.0, 0.0, 1.0, 3.0, 1.0, 0.0, 0.0, 0.0, 1.0, 1.0, 2.0, 0.0, 1.0, 1.0, 3.0, 1.0, 2.0, 0.0, 1.0, 1.0, 1.0, 1.0, 1.0, 5.0, 2.0, 3.0, 2.0, 8.0, 1.0, 1.0, 1.0, 1.0, 1.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0, 4.0, 1.0, 0.0, 2.0, 1.0, 1.0, 19.0, 0.0, 1.0, 0.0, 1.0, 2.0, 1.0, 2.0, 1.0, 1.0, 5.0, 4.0, 2.0, 0.0, 1.0, 2.0, 0.0, 5.0, 0.0, 0.0, 3.0, 1.0, 0.0, 1.0, 1.0, 0.0, 3.0, 2.0, 4.0, 10.0, 2.0, 1.0, 3.0, 1.0, 0.0, 2.0, 1.0, 1.0, 1.0, 1.0, 0.0, 2.0, 17.0, 0.0, 2.0, 3.0, 2.0, 1.0, 0.0, 2.0, 2.0, 1.0, 2.0, 5.0, 2.0, 1.0, 1.0, 1.0, 3.0, 0.0, 1.0, 1.0, 0.0, 4.0, 5.0, 2.0, 2.0, 1.0, 3.0, 0.0, 1.0, 3.0, 1.0, 1.0, 1.0, 0.0, 3.0, 2.0, 1.0, 1.0, 1.0, 1.0, 1.0, 0.0, 0.0, 3.0, 5.0, 0.0, 1.0, 4.0, 0.0, 0.0, 1.0, 6.09]

Answer

coder picture coder · Nov 11, 2016

You could use something simple like:

def freq(lst):
    d = {}
    for i in lst:
        if d.get(i):
            d[i] += 1
        else:
            d[i] = 1
    return d

results:

>>> freq(data)
{0.0: 72, 1.0: 106, 2.0: 40, 3.0: 21, 4.0: 9, 5.0: 10, 6.0: 2, 7.0: 3, 8.0: 2, 9.0: 2, 10.0: 3, 11.0: 1, 15.0: 1, 17.0: 2, 19.0: 1, 6.09: 1, 27.0: 1}

Though Counter worked fine for me (I copy-pasted the data that you posted):

...
>>> from collections import Counter
>>> Counter(data)
Counter({1.0: 106, 0.0: 72, 2.0: 40, 3.0: 21, 5.0: 10, 4.0: 9, 7.0: 3, 10.0: 3, 6.0: 2, 8.0: 2, 9.0: 2, 17.0: 2, 11.0: 1, 15.0: 1, 19.0: 1, 6.09: 1, 27.0: 1})