resolves #90

nd2reader/interface.py

@@ -36,7 +36,7 @@ class Nd2(object):
         :rtype: int
 
         """
-        return self._driver.total_images_per_channel * len(self.channels)
+        return self._metadata.total_images_per_channel * len(self.channels)
 
     def __getitem__(self, item):
         """
@@ -56,7 +56,12 @@ class Nd2(object):
 
         """
         if isinstance(item, int):
-            return self._driver.get_image(item)
+            try:
+                image = self._driver.get_image(item)
+            except KeyError:
+                raise IndexError
+            else:
+                return image
         elif isinstance(item, slice):
             return self._slice(item.start, item.stop, item.step)
         raise IndexError

nd2reader/model/metadata.py

@@ -1,6 +1,6 @@
 class Metadata(object):
     """ A simple container for ND2 metadata. """
-    def __init__(self, height, width, channels, date, fields_of_view, frames, z_levels):
+    def __init__(self, height, width, channels, date, fields_of_view, frames, z_levels, total_images_per_channel):
         self._height = height
         self._width = width
         self._channels = channels
@@ -8,6 +8,7 @@ class Metadata(object):
         self._fields_of_view = fields_of_view
         self._frames = frames
         self._z_levels = z_levels
+        self._total_images_per_channel = total_images_per_channel
 
     @property
     def height(self):
@@ -70,3 +71,7 @@ class Metadata(object):
 
         """
         return self._z_levels
+
+    @property
+    def total_images_per_channel(self):
+        return self._total_images_per_channel

nd2reader/parser/v3.py

@@ -52,7 +52,8 @@ class V3Parser(BaseParser):
         fields_of_view = self._parse_fields_of_view(metadata_dict)
         frames = self._parse_frames(metadata_dict)
         z_levels = self._parse_z_levels(metadata_dict)
-        self._metadata = Metadata(height, width, channels, date, fields_of_view, frames, z_levels)
+        total_images_per_channel = self._parse_total_images_per_channel(metadata_dict)
+        self._metadata = Metadata(height, width, channels, date, fields_of_view, frames, z_levels, total_images_per_channel)
 
     def _parse_date(self, metadata_dict):
         """
@@ -122,7 +123,7 @@ class V3Parser(BaseParser):
         :rtype:     list
 
         """
-        return self._parse_dimension(r""".*?T'\((\d+)\).*?""", metadata_dict)
+        return self._parse_dimension(r""".*?T'?\((\d+)\).*?""", metadata_dict)
 
     def _parse_z_levels(self, metadata_dict):
         """