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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def OnSelectAll(self, event):
 """Select all cells event handler"""


        entry_line = \
            self.main_window.entry_line_panel.entry_line_panel.entry_line

        if wx.Window.FindFocus() != entry_line:
            self.main_window.grid.SelectAll()

        else:
            entry_line.SelectAll()