update the factorial

calc_main.py

@@ -44,6 +44,16 @@ def floor_division():
 
 
     def factorial():
+        num = int(input("enter a number: "))
+        if num < 0:
+        print("Sorry, factorial does not exist for negative numbers")
+        elif num == 0:
+        print("The factorial of 0 is 1")
+        else:
+        for i in range(1,num + 1):
+        factorial = factorial*i
+        print("The factorial of",num,"is:",factorial)
+        return
 
     if choice==1:
         additon()
@@ -61,4 +71,4 @@ def factorial():
         factorial()
     else:
         print("wrong input")
-        exit(0)
+        exit(0)