Flake 8 fixed

Author: PTHARRISH

Notes/3.keywords.py

@@ -105,7 +105,7 @@ def oper():
 # check the object address is same or not If the object address is same it wil return True or return false 
 # string is immutable( cannot be changed once allocated) 
 # hence occupy same memory location 
-print(' ' is ' ') 
+# print(' ' is ' ') 
 a=10
 b=10
 print(a is b)# check the object address is same or not If the object address is same it wil return True or return false

leet code/addtwonumbers.py

@@ -1,3 +1,10 @@
+from typing import Optional
+
+class ListNode:
+    def __init__(self, val=0, next=None):
+        self.val = val
+        self.next = next
+
 class Solution:
     def addTwoNumbers(self, l1: Optional[ListNode], l2: Optional[ListNode]) -> Optional[ListNode]:
         head=l1