[wxPython-users] Re: Question about Grid or events ?

[Robin Dunn]

Hugues JEAN-BAPTISTE wrote:
> I have tested the next :
> 
> def OnBtVal(self, evt) :
>   for row in range(gr.GetNumberRows()) :
>       wx.CallAfter(self.ProcRow, row)
> def ProcRow(self, row) :
>    Do manythings ....
>    gr.SetValue(row, col, 'Row finished ...')
>    gr.Refresh()
>    wx.Yield()
> 
> I have the message :
> 
> Traceback (most recent call last):
>  File "C:\PYTHON23\Lib\site-packages\wx-2.6-msw-ansi\wx\_core.py", line 
> 13539,
> in <lambda>
>    lambda event: event.callable(*event.args, **event.kw) )
>  File "..\paie.1.7\calcul.py", line 441, in CalculSal
>    wx.Yield()
>  File "C:\PYTHON23\Lib\site-packages\wx-2.6-msw-ansi\wx\_core.py", line 
> 7447, i
> n Yield
>    return _core_.Yield(*args, **kwargs)
> wx._core.PyAssertionError: C++ assertion "wxAssertFailure" failed in 
> ..\..\src\m
> sw\app.cpp(684): wxYield called recursively
> 
> I don't understand the problem !...
> 

A wx.Yield call happened while another wx.Yield call was already in 
progress.

wx.Yield essentially starts a nested event loop, including processing of 
pending and idle events.  So when you use CallAfter it makes a pending 
event, when that event is processed and your function calls wxYield, it 
processes the pending events again and eventually gets to the next 
wx.Yield call, which processes pending events again which...

Take a look at http://wiki.wxpython.org/LongRunningTasks for ideas on 
how to better handle doing things that may take a long time to run.

-- 
Robin Dunn
Software Craftsman
http://wxPython.org  Java give you jitters?  Relax with wxPython!