make finding tops of block stacks more efficient in taexportpython

1 files changed, 12 insertions, 7 deletions

diff --git a/TurtleArt/taexportpython.py b/TurtleArt/taexportpython.py
index 62065ce..809679d 100644
--- a/TurtleArt/taexportpython.py
+++ b/TurtleArt/taexportpython.py
@@ -30,7 +30,7 @@ import util.codegen as codegen
 
 from talogo import LogoCode
 from taprimitive import (Primitive, PyExportError)
-from tautils import (debug_output, find_top_block)
+from tautils import (debug_output, find_group, find_top_block)
 
 
 
@@ -77,14 +77,19 @@ PAT_IDENTIFIER_ILLEGAL_CHAR = re.compile("[^A-Za-z0-9_]")
 
 def save_python(tw):
     """ Find all the action stacks and turn each into python code """
-    stacks_of_blocks = tw.just_blocks()
+    all_blocks = tw.just_blocks()
+    blocks_covered = set()
+    tops_of_stacks = []
+    for block in all_blocks:
+        if block not in blocks_covered:
+            top = find_top_block(block)
+            tops_of_stacks.append(top)
+            block_stack = find_group(top)
+            blocks_covered.update(set(block_stack))
+
     snippets = [_SETUP_CODE_START]
-    for block in stacks_of_blocks:
+    for block in tops_of_stacks:
         # TODO name of action stack?
-        # TODO there must be a more efficient way than finding the top from each block
-        top = find_top_block(block)
-        if block != top:
-            continue
         pythoncode = _action_stack_to_python(block, tw.lc)
         snippets.append(pythoncode)
         snippets.append(linesep)