From 4c842e06a1187f043fee396f3d39081f34317521 Mon Sep 17 00:00:00 2001
From: "W. Trevor King" <wking@drexel.edu>
Date: Sat, 21 Aug 2010 13:44:05 -0400
Subject: [PATCH] Tracked down problems saving playlists with loaded curves to
 numpy.dtype

---
 hooke/playlist.py | 27 ++++++++++++++++++++++-----
 1 file changed, 22 insertions(+), 5 deletions(-)

diff --git a/hooke/playlist.py b/hooke/playlist.py
index 9ee3125..b996a5f 100644
--- a/hooke/playlist.py
+++ b/hooke/playlist.py
@@ -27,6 +27,24 @@ import os
 import os.path
 import types
 
+if False: # YAML dump debugging code
+    """To help isolate data types etc. that give YAML problems.
+
+    This is usually caused by external C modules (e.g. numpy) that
+    define new types (e.g. numpy.dtype) which YAML cannot inspect.
+    """
+    import yaml.representer
+    import sys
+    def ignore_aliases(data):
+        print data, type(data)
+        sys.stdout.flush()
+        if data in [None, ()]:
+            return True
+        if isinstance(data, (str, unicode, bool, int, float)):
+            return True
+    yaml.representer.SafeRepresenter.ignore_aliases = staticmethod(
+        ignore_aliases)
+
 import yaml
 from yaml.representer import RepresenterError
 
@@ -103,10 +121,10 @@ class NoteIndexList (list):
                 continue
             try:
                 yaml.dump((k,v))
-            except (TypeError, RepresenterError), e:
+            except RepresenterError, e:
                 raise NotImplementedError(
-                    'cannot convert %s.%s = %s (%s) to YAML'
-                    % (owner.__class__.__name__, k, v, type(v)))
+                    'cannot convert %s.%s = %s (%s) to YAML\n%s'
+                    % (owner.__class__.__name__, k, v, type(v), e))
 
     def _setup_item(self, item):
         """Perform any required initialization before returning an item.
@@ -197,10 +215,9 @@ class Playlist (NoteIndexList):
         self._ignored_attrs.extend([
                 '_item_ignored_attrs', '_item_default_attrs',
                 '_loaded'])
-        self._item_ignored_attrs = []
+        self._item_ignored_attrs = ['data']
         self._item_default_attrs = {
             'command_stack': [],
-            'data': None,
             'driver': None,
             'info': {},
             'name': None,
-- 
2.26.2