CODEWITHSUNDEEP
pythondebuggingpycharmwxpython
uri
uri

Reputation: 431

debugging a wxPython application under PyCharm leads to termination on every unhandled exception

Under wxPython when an unhandled exception arises in the main loop the traceback is printed and the exception is ignored. Not so when debugging under PyCharm. Then the unhandled exception leads to termination of the process. Also, this is new behavior as previous versions of PyCharm did not behave this way.

Take the following test code:

import wx
import wx.lib.sized_controls as sc

def Raise(evt=None):
    raise Exception('error')

app = wx.App()
frame = sc.SizedFrame(None,-1,'hello')
p = frame.GetContentsPane()
b = wx.Button(p,-1,'press')
frame.Bind(wx.EVT_BUTTON,Raise,b)
frame.Show()
app.MainLoop()

Pressing the button when running this normally results in an exception printed and ignored. When running this under PyCharm debug mode the process terminates. Is there a way to change this behavior?

Windows10, Python3.6, wxPython 4.0.4, PyCharm 2019.3

Upvotes: 0

Views: 247

Answers (1)

RobinDunn
RobinDunn

Reputation: 6206

Like most Python debuggers, PyCharm installs its own exception handler as sys.excepthook, so whenever there is different behavior between normal runs and debugger runs that is the place to start looking. For example, if you look at the list of Breakpoints for your project you'll also see options for breaking on exceptions. That stuff is implemented in the new excepthoot function. If all else fails, you can look at the pydev code that PyCharm uses for launching and communicating with the debuggee, and see what it's doing in it's excepthook-related code, which may give some clues about how to work around this issue.

I'm not using it as much anymore so I may be misremembering, but I seem to recall that there was an option somewhere in PyCharm for stopping on or ignoring unhandled exceptions, or perhaps for ignoring exceptions raised from specific locations, but I'm not seeing either of them now.

OTOH, catching exceptions before the end of an event handler or other callback function is always a good idea.

Upvotes: 1

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