Question

I’m using the command

select video_info count(distinct src_ip) from videoinfo 
  group by video_info 
  order by count(distinct src_ip) DESC

to fetch 2 columns of data, the first column represents identifiers for each video items, the second column records how many times they have been downloaded.

I also want to calculate, for example, 5% of videos have been downloaded twice, 10% videos have been downloaded 10 times, then record the percentage numbers and the download times into two arrays.

Does Mysql support such calculation? or I need to switch to Python to do that? If so, how to do that in Python?

Answer 1

In Python you can use this:

cur.execute("SELECT video_info, COUNT(distinct src_ip) "
            "FROM videoinfo "
            "GROUP BY video_info "
            "ORDER BY COUNT(DISTINCT src_ip) DESC")

counter = dict(cur)
for n in xrange(1, max(counter.itervalues()) + 1):
    perc = 100. / sum(1 for nb in counter.itervalues() if nb == n) / len(counter)
    if perc:
        print '%.f%% videos have been downloaded %d times' % (perc, n)

With counter = {'a': 1, 'b': 1, 'c': 2, 'd': 1, 'e': 2, 'f': 3} this prints:

50% videos have been downloaded 1 times
33% videos have been downloaded 2 times
17% videos have been downloaded 3 times