Converting click count data to JSON
Trailing semicolons

At many places there is a ; at the end of the line.
It's completely unnecessary in Python and you should remove those.

Appending to arrays

At several places you are appending values to arrays in a strange way, for example:


    datedict[val[0]] = datedict[val[0]] + [val[1]];



The common and shorter way to do this is using .append():

    datedict[val[0]].append(val[1])


Augmented assignment operator +=

Instead of:


l = l + 1



This is shorter and better:

l += 1


Use list comprehensions

Instead of:


datearr = []
for dat in daterange(mindate, today):
    datearr = datearr + [datedict[dat]]



You can use a list comprehension, a powerful feature of Python:

datearr = [datedict[dat] for dat in daterange(mindate, today)]