I see that your using Python 3, what book are you using? If it's written by Mark Summerfield I have the same book, and in that case, just keep reading.
Otherwise, to set up a low variable set to the first input I would:
python
total, count, high = 0, 0, 0
a = []
while True:
while True:
line = input("Enter a value (Enter to finish): ")
if line:
try:
low = int(line)
except ValueError as err:
print(err)
continue
else:
exit()
line = input("Enter a value (Enter to finish): ")
...
I use "..." to represent the rest of the code you already have.
You may notice that the loops to initialize low looks a lot like the code you already have, and this is fine for now, but as you learn more you want to use defined functions (these call pre-written code).
Also you see that in the else statement of setting low, I call exit(), this is because you must leave both while loops. Normally you do not call exit() or quit() within your program, but again here it is fine, later you will see if you want to exit you should call sys.exit(), and you have not come that far yet.
This post has been edited by code_m: 31 May, 2009 - 12:43 PM