Update zigzagtraversal comments

Author: kumailn

Python/Binary_Tree_Zig_Zag_Traversal.py

@@ -4,21 +4,28 @@
 #Difficulty: Medium 
 
 def zigzagLevelOrder(root):
-        """
-        :type root: TreeNode
-        :rtype: List[List[int]]
-        """
+        #If the root is null, return an empty list
         if not root: return []
+        #Create variables r (result), q (queue), and c (current queue)
         r, q, c = [[]], [root], []
+        #Keep track of if we're going left or right in our zigzag traversal
         zig = False
+        #As long as the queue is not empty
         while q:
+            #For each item in the queue
             for i in q:
+                #Append item to the end of the result list
                 r[-1] += [i.val]
+                #If left and right children exist, add them to current queue in order of left to right
                 if i.left: c += [i.left]
                 if i.right: c += [i.right]
+            #Reset queue to current queue and current queue to an empty list
             q, c = c, []
+            #If we're going right to left, reverse the last item in our results list
             if zig:
                 r[-1] = r[-1][::-1]
+            #Negate out boolen so we go the opposite direction next time
             zig = not zig
+            #If our queue still is non null, add an empty list to our result because we sill have entries to fill
             if q: r += [[]]
         return r