# Here is a main program that totals up a list. No function is defined.

list=[5,7,9, 12]
total=0
i=0
while i<len(list):
	total=total+list[i]
	i=i+1
print total



********************
# Here's essentially the same program, but totalList is a function 
#   called from the 'main' program

def totalList(list):
	total=0
	i=0
	while i<len(list):
		total=total+list[i]
		i=i+1
	return total


numbers=[5,7,9,12]
result = totalList(numbers)
print result



1. Can you label the parts of the code: 

	function, function call, loop variable, accumulator variable, parameter, library function call, index.

2. Note that in the 'main' the list is called 'numbers' and in the function its called 'list'. Also, in the main
     the total is called 'result' and in the function its called 'total'. Explain why the program still works.

3. Can you trace the program, showing how all variables change?

4. Can you write a program that does something else to a list, e.g., doubles every element?

5. Can you write the program so that the end-user can input the elements of the list and so that the end-user
     can try it with many different lists (i.e., put a loop in main).