In <1enj0att6bkrnvb81rhma5dbuk3h28a...@4ax.com> Seymore4Head <Seymore4Head@Hotmail.invalid> writes:
> I'm still doing practice problems. I haven't heard from the library > on any of the books I have requested. > http://www.practicepython.org/exercise/2014/04/16/11-check-primality-functions.html > This is not a hard problem, but it got me to thinking a little. A > prime number will divide by one and itself. When setting up this > loop, if I start at 2 instead of 1, that automatically excludes one of > the factors. Then, by default, Python goes "to" the chosen count and > not "through" the count, so just the syntax causes Python to rule out > the other factor (the number itself). > So this works: > while True: > a=random.randrange(1,8) > print (a) > for x in range(2,a): > if a%x==0: > print ("Number is not prime") > break > wait = input (" "*40 + "Wait") > But, what this instructions want printed is "This is a prime number" > So how to I use this code logic NOT print (not prime) and have the > logic print "This number is prime" There are two basic tactics you can use: 1. Initialize an "isprime" flag to True at the top of the while loop. In the for loop, replace the print statement with a statement that sets isprime to False. After the for loop, insert a check on isprime, and print "This number is prime" if isprime is still True. 2. Create a separate function just for testing if a number is prime, which returns True or False. Then call that function within your while loop. -- John Gordon Imagine what it must be like for a real medical doctor to gor...@panix.com watch 'House', or a real serial killer to watch 'Dexter'. -- https://mail.python.org/mailman/listinfo/python-list
