Merge pull request geekcomputers#1234 from VictorOlly/patch-1

Prime_number update.

Author: geekcomputers

Prime_number

@@ -1,11 +1,22 @@
-num=int(input("Enter a number"))
-if num>1:
+#if user input is not an int, shows error message
+while True:
+    try:
+        num = int(input("Enter a number: "))
+        break
+    except ValueError:
+        print("Invalid input.")
+
+if num > 1:
+   # check for factors
     for i in range(2,num):
-        if(num%i)==0:
-          print(num,"is not a prime number")
-          print(i,"times",num//i,"is",num)
-          break
-        else:
-          print(num,"is a prime number")
+        if (num % i) == 0:
+            print(num,"is not a prime number")
+            print(i,"times",num//i,"is",num)
+            break
+    else:
+        print(num,"is a prime number")
+       
+# if input number is less than
+# or equal to 1, it is not prime
 else:
     print(num,"is not a prime number")