Merge pull request #1533 from jakevdp/anim-error

dmcdougall · dmcdougall · commit dd92a4309029 · 2012-11-30T14:22:41.000-08:00
ENH: raise a more informative error
diff --git a/lib/matplotlib/animation.py b/lib/matplotlib/animation.py
@@ -657,7 +657,13 @@ def save(self, filename, writer=None, fps=None, dpi=None, codec=None,
             else:
                 import warnings
                 warnings.warn("MovieWriter %s unavailable" % writer)
-                writer = writers.list()[0]
+
+                try:
+                    writer = writers.list()[0]
+                except IndexError:
+                    raise ValueError("Cannot save animation: no writers are "
+                                     "available. Please install mencoder or "
+                                     "ffmpeg to save animations.")
 
         verbose.report('Animation.save using %s' % type(writer),
                        level='helpful')
