title: Creating Python Factorial
body: <p>Evening,</p>
  
  <p>I'm an intro to python student having some trouble.
  I'm trying to make a python factorial program. It should prompt the user for n and then calculate the factorial of n UNLESS the user enters -1. I'm so stuck, and the prof suggested we use the while loop. I know I didn't even get to the 'if -1' case yet. Don't know how to get python to calc a factorial with out just blatantly using the math.factorial function. </p>
  
  <pre><code>import math
  
  num = 1
  n = int(input("Enter n: "))
  
  while n &gt;= 1:
       num *= n
  
  print(num)
  </code></pre>