trouble with functions "def", calling/defining them

[bowlofred]

But line 32 above is where you call it, and there you have not supplied any arguments. One possible call might be:

showIncome(2, 5, 12, 100, 200, 500)

This means when showIncome() is run, num_aTickets is set to 2, num_bTickets is set to 5, etc. Without those values passed in, the function doesn't know what they should be set to.