[PythonReports-users] Adding a Field to Detail band

When I do:

1. Click on "New Template"
2. create "data"

 >>> data = ds.query(db.Cellarbook).all()
 >>> data
[Cellarbook(storagelocation=None), Cellarbook(storagelocation=None), 
Cellarbook(storagelocation=None), Cellarbook(storagelocation=None), 
Cellarbook(storagelocation=None), Cellarbook(storagelocation=None), 
Cellarbook(storagelocation=None), Cellarbook(storagelocation=None), 
Cellarbook(storagelocation=None)]

3. Click on "New Field"
4. Click within "Detail" band I get this exception:

wx._core.PyAssertionError: C++ assertion "Assert failure" failed at 
..\..\src\propgrid\propgridpagestate.cpp(1673) in 
wxPropertyGridPageState::PrepareToAddItem(): wxPropertyGrid item with 
name "data"  ... (truncated)
File "c:\dev\twcbv4\twcbsrc\reports\dbtest.py", line 66, in <module>
   ptedit()
File "c:\Python27\Lib\site-packages\PythonReports\editor\editor.py", 
line 11, in main
   _app.MainLoop()
File "c:\Python27\Lib\site-packages\wx-2.9.4-msw\wx\_core.py", line 
8660, in MainLoop
   wx.PyApp.MainLoop(self)
File "c:\Python27\Lib\site-packages\wx-2.9.4-msw\wx\_core.py", line 
7952, in MainLoop
   return _core_.PyApp_MainLoop(*args, **kwargs)
File "c:\Python27\Lib\site-packages\wx-2.9.4-msw\wx\lib\ogl\_canvas.py", 
line 249, in OnMouseEvent
   self.OnLeftClick(x, y, keys)
File 
"c:\Python27\Lib\site-packages\PythonReports\editor\elements\design.py", 
line 94, in OnLeftClick
   self.add_element(_class_to_create(self, x, y))
File 
"c:\Python27\Lib\site-packages\PythonReports\editor\elements\design.py", 
line 482, in __init__
   self.init_shape(parent_canvas, x, y, sync_box)
File 
"c:\Python27\Lib\site-packages\PythonReports\editor\elements\design.py", 
line 310, in init_shape
   self.synchronize_box()
File 
"c:\Python27\Lib\site-packages\PythonReports\editor\elements\design.py", 
line 458, in synchronize_box
   self.app.focus_set(self)
File 
"c:\Python27\Lib\site-packages\PythonReports\editor\application.py", 
line 46, in focus_set
   self.frame.property_grid.setup_by_element(listener)
File 
"c:\Python27\Lib\site-packages\PythonReports\editor\propertiesgrid.py", 
line 261, in setup_by_element
   self.append_atributes(_tag, _body)
File 
"c:\Python27\Lib\site-packages\PythonReports\editor\propertiesgrid.py", 
line 308, in append_atributes
   self.Append(wxpg.PropertyCategory(tag))
File "c:\Python27\Lib\site-packages\wx-2.9.4-msw\wx\propgrid.py", line 
1096, in Append
   return _propgrid.PropertyGridInterface_Append(*args, **kwargs)

Any hints on what I am doing wrong?

Werner