filtered traitlet

[jchuahtacc]

Added filtered traitlet which allows python client to retrieve indices of what is currently viewable (after filtering)

[TimShawver]

It seems like your code isn't working with grids that have a Timestamp index. I get the following error when running #2 under Example 1 in the demo notebook https://github.com/quantopian/qgrid/blob/master/qgrid_demo.ipynb

qgrid.show_grid(spy) --------------------------------------------------------------------------- TypeError Traceback (most recent call last) <ipython-input-9-7f2f26238472> in <module>() ----> 1 qgrid.show_grid(spy) /Users/tshawver/repo/qgrid-master/qgrid/grid.pyc in show_grid(data_frame, show_toolbar, remote_js, precision, grid_options) 205 grid = QGridWidget(df=data_frame, precision=precision, 206 grid_options=grid_options, --> 207 remote_js=remote_js) 208 209 if show_toolbar: /Users/tshawver/repo/qgrid-master/qgrid/grid.pyc in __init__(self, *args, **kwargs) 249 self._selected_rows = [] 250 if self.df is not None: --> 251 self._update_table() 252 253 def _grid_options_default(self): /Users/tshawver/repo/qgrid-master/qgrid/grid.pyc in _update_table(self) 273 df.index.name = 'Index' 274 --> 275 self.filtered = df.index.tolist() 276 277 if type(df.index) == pd.core.index.MultiIndex: /usr/local/lib/python2.7/site-packages/traitlets/traitlets.pyc in __set__(self, obj, value) 581 raise TraitError('The "%s" trait is read-only.' % self.name) 582 else: --> 583 self.set(obj, value) 584 585 def _validate(self, obj, value): /usr/local/lib/python2.7/site-packages/traitlets/traitlets.pyc in set(self, obj, value) 570 # we explicitly compare silent to True just in case the equality 571 # comparison above returns something other than True/False --> 572 obj._notify_trait(self.name, old_value, new_value) 573 574 def __set__(self, obj, value): /usr/local/lib/python2.7/site-packages/traitlets/traitlets.pyc in _notify_trait(self, name, old_value, new_value) 1135 new=new_value, 1136 owner=self, -> 1137 type='change', 1138 )) 1139 /usr/local/lib/python2.7/site-packages/ipywidgets/widgets/widget.pyc in notify_change(self, change) 366 # Send new state to front-end 367 self.send_state(key=name) --> 368 LoggingConfigurable.notify_change(self, change) 369 370 #------------------------------------------------------------------------- /usr/local/lib/python2.7/site-packages/traitlets/traitlets.pyc in notify_change(self, change) 1172 c = getattr(self, c.name) 1173 -> 1174 c(change) 1175 1176 def _add_notifiers(self, handler, name, type): /Users/tshawver/repo/qgrid-master/qgrid/grid.pyc in filtered_changed(self, change) 394 self.filtered = [ ] 395 for index in change['new']: --> 396 self.filtered.append(int(index)) 397 TypeError: int() argument must be a string or a number, not 'Timestamp'