Check if iterator has length

tacaswell · tacaswell · commit b57c6dc0b154 · 2013-11-30T15:26:00.000-06:00
If an iterable is passed into `FuncAnimation` check if it has `__len__` before trying to take it's length closes #1769
diff --git a/lib/matplotlib/animation.py b/lib/matplotlib/animation.py
@@ -1000,7 +1000,8 @@ def __init__(self, fig, func, frames=None, init_func=None, fargs=None,
             self._iter_gen = frames
         elif iterable(frames):
             self._iter_gen = lambda: iter(frames)
-            self.save_count = len(frames)
+            if hasattr(frames, '__len__'):
+                self.save_count = len(frames)
         else:
             self._iter_gen = lambda: xrange(frames).__iter__()
             self.save_count = frames
