first approx to grapher

trees/Siterator.py

@@ -4,14 +4,13 @@ __copyright__ = "Copyright 2020, Ricardo Montañana Gómez"
 __license__ = "MIT"
 __version__ = "0.9"
 Inorder iterator for the binary tree of Snodes
-Uses LinearSVC
 '''
 
 from trees.Snode import Snode
 
 
 class Siterator:
-    """Inorder iterator
+    """Stree preorder iterator
     """
 
     def __init__(self, tree: Snode):
@@ -22,13 +21,13 @@ class Siterator:
         return self
 
     def _push(self, node: Snode):
-        while (node is not None):
-            self._stack.insert(0, node)
-            node = node.get_down()
+        if node is not None:
+            self._stack.append(node)
 
     def __next__(self) -> Snode:
         if len(self._stack) == 0:
             raise StopIteration()
         node = self._stack.pop()
         self._push(node.get_up())
+        self._push(node.get_down())
         return node