Skip to main content

Let’s Think Python: COMSC020 PreTeXt Interactive Edition

Section 6.9 Eliminating Repetitive Code

The key to eliminating the duplicate code is to take the calculation of the total price and make it a function with two parameters: the unit price and the quantity purchased. This function will return the total price. We can then call this function twice: once with the information for the first purchase, and again with the information for the second purchase.
Here are some important things to note:
  • The names of the parameters (price and quantity) do not have to be the same as the names of the arguments.
  • Arguments are copied into the parameters in the order they appear. In the call calculate_total(price1, qty1), the value of argument price1 is copied into parameter price, and the value of argument qty1 is copied into paramter quantity.
  • The function definition (starting in line 1) must appear before the function is called (in lines 18 and 19). We’ll examine this in a bit more detail on the next page.
<Prev^TopNext>