Added program to find factorial of number #9

Author: seancyw

Code/factorial.py

@@ -0,0 +1,15 @@
+#program to find the factorial of a number provided by a user
+
+if __name__ == "__main__":
+    number = int(raw_input("Enter a number to get its factorial: "))
+    factorial = 1
+
+    if number < 0:
+        print("Sorry, factorial doesn't exist for negative numbers!")
+    elif number == 0:
+        print("The factorial of 0 is 1")
+    else:
+        for i in range(1, number + 1):
+            factorial = factorial * i
+        print "The factorial of %r is %r" % (number, factorial)
+