Python-сообщество

 def view_records(self):
        summ = self.db.c.execute('''SELECT SUM(costs) FROM finance''')
        money_mass = self.db.c.execute('''SELECT costs FROM finance''')
        money_mass.fetchall()
        end = 0
        for i in money_mass:
            self.stats_field.create_arc(start=end, extend=3.6*(i//summ * 100), fill = "black")
            end += 3.6*(i//summ * 100)

 COLORS = ('black', 'blue', 'green', 'grey', 'purple', 'orange', 'maroon', 'gold')  #если не хватит, добавить цветов

     def view_records(self):
        summ = self.db.c.execute('''SELECT SUM(costs) FROM finance''').fetchone()
        money_mass = self.db.c.execute('''SELECT costs FROM finance''').fetchall()
        end = 0
        for i,m in enumerate(money_mass):
            ext = 360 * m[0] / summ[0]
            self.stats_field.create_arc(20, 20, 200, 200, start=end, extent=ext, fill=COLORS[i])
            end += ext