Updated validation.py python script

Course3/Lab4/validations.py

@@ -12,13 +12,21 @@ def validate_user(username, minlen):
     # Usernames can't be shorter than minlen
     if len(username) < minlen:
         return False
-    # Usernames can only use letters, numbers, dots and underscores
+    # Usernames can only use letters and numbers
     if not re.match('^[a-z0-9._]*$', username):
         return False
     # Usernames can't begin with a number
     if username[0].isnumeric():
         return False
+    # Usernames cant begin with dot and underscore
+    if username[0] == '_':
+        return False
+    if username[0] == '.':
+        return False
     return True
 
-
+print(validate_user("blue.kale", 3)) # True
+print(validate_user(".blue.kale", 3)) # Currently True, should be False
+print(validate_user("red_quinoa", 4)) # True
+print(validate_user("_red_quinoa", 4)) # Currently True, should be False