[WxPython] Why does an error occur after editing a grid cell?

[ioprst]

There is a dialogue on which there is a panel on which there is a grid.

Each grid column is assigned its own editor (in a class derived from GridTableBase)

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class StatePanel(wx.Panel):       def __init__(self, parent, states):         super().__init__(parent)           topsizer = wx.FlexGridSizer(rows=1, cols=2, vgap=10, hgap=10)           self.grid = CustomGrid(self, size=(-1, 100))         self.grid.Bind(wx.grid.EVT_GRID_CELL_CHANGED, self.OnGridCellChange)         topsizer.Add(self.grid, proportion=1, flag=wx.EXPAND)           self.SetSizer(topsizer)           defaultValue = _StateInfos(0, '0', 'Состояние 0', YELLOW)           self.states = states         if not self.states:             self.states.append(defaultValue.copy())           self.table = StateTable(self.states, GetStateTableColnames())     self.RefreshStates()   def RefreshStates(self):     data = []     for num, state in enumerate(self.states):         state.Number = num + 1         data.append(state)     self.table.SetData(data)     self.table.ResetView(self.grid)   def OnGridCellChange(self, event):     row, col = event.GetRow(), event.GetCol()     colname = self.table.GetColLabelValue(col, False)     value = self.table.GetValue(row, col)     message = None       if colname == 'Code':         if not value:             message = 'Значение кода не может быть пустым.'         else:             for r in range(self.table.GetNumberRows()):                 if r != row:                     code = self.table.GetValueByName(r, 'Code')                     if value == code:                         message = f'Код {value} уже используется.'                         break       if message is not None:         wx.CallAfter(showErrorMessage, message)         event.Veto()     else:         event.Skip()

In self.table.ResetView, the StateTable.ResetView method is called

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class StateTable(wx.grid.GridTableBase):        ...          def ResetView(self, grid):         """         (wx.grid.Grid) -> Reset the grid view.   Call this to         update the grid if rows and columns have been added or deleted         """         grid.CloseEditControl()         grid.BeginBatch()         for current, new, delmsg, addmsg in [             (                 self._rows,                 self.GetNumberRows(),                 wx.grid.GRIDTABLE_NOTIFY_ROWS_DELETED,                 wx.grid.GRIDTABLE_NOTIFY_ROWS_APPENDED             ),             (                 self._cols,                 self.GetNumberCols(),                 wx.grid.GRIDTABLE_NOTIFY_COLS_DELETED,                 wx.grid.GRIDTABLE_NOTIFY_COLS_APPENDED             )         ]:             if new < current:                 msg = wx.grid.GridTableMessage(self, delmsg, new, current-new)                 grid.ProcessTableMessage(msg)             elif new > current:                 msg = wx.grid.GridTableMessage(self, addmsg, new-current)                 grid.ProcessTableMessage(msg)                 self.UpdateValues(grid)         grid.EndBatch()           self._rows = self.GetNumberRows()         self._cols = self.GetNumberCols()         # update the column rendering scheme         self._updateColAttrs(grid)           # update the scrollbars and the displayed part of the grid         grid.AdjustScrollbars()         grid.ForceRefresh()       def _updateColAttrs(self, grid):         for row in range(self.GetNumberRows()):             for col in range(self.GetNumberCols()):                 editor = None                 renderer = None                 colname = self.GetColLabelValue(col, False)                   if col != 0:                     grid.SetReadOnly(row, col, False)                       if colname == 'Code':                         editor = wx.grid.GridCellNumberEditor()                         renderer = wx.grid.GridCellNumberRenderer()                       elif colname == 'Text':                         editor = wx.grid.GridCellTextEditor()                         renderer = wx.grid.GridCellStringRenderer()                       elif colname == 'Text colour':                         editor = GridCellColourEditor()                         renderer = GridCellColourRenderer()                   else:                     grid.SetReadOnly(row, col, True)                   grid.SetCellEditor(row, col, editor)                 grid.SetCellRenderer(row, col, renderer)

If I edit any cell and close the dialog, an error occurs

Error:
wx._core.wxAssertionError: C++ assertion "GetEventHandler() == this" failed at ..\..\src\common\wincmn.cpp(478) in wxWindowBase::~wxWindowBase(): any pushed event handlers must have been removed

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Python37-32\lib\site-packages\wx\lib\agw\customtreectrl.py", line 8183, in OnInternalIdle
    if not self.HasAGWFlag(TR_MULTIPLE) and not self.GetSelection():
  File "C:\Python37-32\lib\site-packages\wx\lib\agw\customtreectrl.py", line 3534, in HasAGWFlag
    return bool(self._agwStyle & flag)
SystemError: <class 'bool'> returned a result with an error set

I saw the topic: https://github.com/wxWidgets/Phoenix/issues/627

I did everything as suggested in the solution, but this does not solve the problem.

The problem is solved only if in the OnGridCellChange method at the end call self.table._updateColAttrs (self.grid).

Why?

[ioprst]

It solved my problem

Table:

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class StateTable(CustomTable):       ...       def _updateColAttrs(self, grid):         for row in range(self.GetNumberRows()):             for col in range(self.GetNumberCols()):                 editor = None                 renderer = None                 colname = self.GetColLabelValue(col, False)                   if col != 0:                     grid.SetReadOnly(row, col, False)                       if colname == 'Code':                         editor = wx.grid.GridCellNumberEditor()                         renderer = wx.grid.GridCellNumberRenderer()                     ...                   else:                     grid.SetReadOnly(row, col, True)                   # !!!!!! DECISION !!!!!!                 currentEditor = grid.GetCellEditor(row, col)                 currentEditor.DecRef()                   grid.SetCellEditor(row, col, editor)                 grid.SetCellRenderer(row, col, renderer)             self.ResizeRow(grid, row)

Grid:

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class StatePanel(wx.Panel):       def __init__(self, parent, states):         ...           self.grid = CustomGrid(self, size=(-1, 120))         self.grid.Bind(wx.EVT_WINDOW_DESTROY, self.OnGridDestroy)         ...       def OnGridDestroy(self, event):         self.table._updateColAttrs(self.grid)         event.Skip()

[Larz60+]

Thanks for sharing answer so others with same problem can benefit.