tuple as dictionary key

Hello!

Code inspector doesn't like when i write (it's allowed in python, though):

        for row in Salary.objects.all():

            j, p, m = row.job_id, row.payment_id, row.movement_type

            if (j,p,m) not in self.salaries:

                self.salaries[j,p,m] = []

            self.salaries[j,p,m].append((row.dt_start, row.dt_end, row.rate))

the following code marks append method as unrecognized

if i change it to

        for row in Salary.objects.all():
            j, p, m = row.job_id, row.payment_id, row.movement_type
            if (j,p,m) not in self.salaries:
                self.salaries[(j,p,m)] = []
            self.salaries[(j,p,m)].append((row.dt_start, row.dt_end, row.rate))

i think that the first example is also valid, so it needs to be fixed