Refactor offline

This refactoring includes some slicing and performance improvement attempts.

The slicing is still experimental and has some flaws:

• fancy indexing over thousands of elements might be horrible slow, eg f.events.tracks[idx_list, 0] where idx_list is a huge list of indices
• trivial problem of iterating: for track in f.evens.tracks does not stop after the last element
• meaningless indexing: f.events[5][23][420] is simply f.events[420] since the index/slice is not chained but overwritten when propagated. We need custom checks whether it makes sense
  • events are flat lists, so [x][y] does not make sense, it should throw an error
  • f.events[5:23][4] should effectively be the same as f.events[9] due to chaining of slice/index

km3io/tools.py

@@ -105,22 +105,11 @@ class Branch:
 
     def __getitem__(self, item):
         """Slicing magic"""
-        if isinstance(item, (int, slice, tuple)):
-            return self.__class__(self._tree,
-                                  self._mapper,
-                                  index_chain=self._index_chain + [item],
-                                  keymap=self._keymap,
-                                  subbranchmaps=self._subbranchmaps)
-
-        # if isinstance(item, tuple):
-        #     return self[item[0]][item[1]]
-
         if isinstance(item, str):
             return self.__getkey__(item)
-
         return self.__class__(self._tree,
                               self._mapper,
-                              index_chain=self._index_chain + [np.array(item)],
+                              index_chain=self._index_chain + [item],
                               keymap=self._keymap,
                               subbranchmaps=self._subbranchmaps)