Helpful error message if trying to run the ipythonx entry point without

wx installed.

IPython/frontend/wx/ipythonx.py

@@ -1,91 +1,100
 #!/usr/bin/env python
 """
 Entry point for a simple application giving a graphical frontend to
 ipython.
 """
 
-import wx
+try:
+    import wx
+except ImportError, e:
+    e.message = """%s
+________________________________________________________________________________
+You need wxPython to run this application.
+""" % e.message
+    e.args = (e.message, ) + e.args[1:]
+    raise e
+
 from wx_frontend import WxController
 import __builtin__
 
 class IPythonXController(WxController):
     """ Sub class of WxController that adds some application-specific
         bindings.
     """
 
     debug = False
 
     def __init__(self, *args, **kwargs):
         WxController.__init__(self, *args, **kwargs)
         self.ipython0.ask_exit = self.do_exit
 
 
     def _on_key_down(self, event, skip=True):
         # Intercept Ctrl-D to quit
         if event.KeyCode == ord('D') and event.ControlDown() and \
                 self.input_buffer == '' and \
                 self._input_state == 'readline':
             wx.CallAfter(self.ask_exit)
         else:
             WxController._on_key_down(self, event, skip=skip) 
 
 
     def ask_exit(self):
         """ Ask the user whether to exit.
         """
         self.write('\n')
         self.capture_output()
         self.ipython0.shell.exit()
         self.release_output()
         wx.Yield()
         if not self.ipython0.exit_now:
             self.new_prompt(self.input_prompt_template.substitute(
                                 number=self.last_result['number'] + 1))
  
 
     def do_exit(self):
         """ Exits the interpreter, kills the windows.
         """
         WxController.do_exit(self)
         self.release_output()
         wx.CallAfter(wx.Exit)
 
 
 
 class IPythonX(wx.Frame):
     """ Main frame of the IPythonX app.
     """
 
     def __init__(self, parent, id, title):
         wx.Frame.__init__(self, parent, id, title, size=(300,250))
         self._sizer = wx.BoxSizer(wx.VERTICAL)
         self.shell = IPythonXController(self)
         self._sizer.Add(self.shell, 1, wx.EXPAND)
         self.SetSizer(self._sizer)
         self.SetAutoLayout(1)
         self.Show(True)
 
 
 def main():
     from optparse import OptionParser
     usage = """usage: %prog [options]
 
 Simple graphical frontend to IPython, using WxWidgets."""
     parser = OptionParser(usage=usage)
     parser.add_option("-d", "--debug",
                     action="store_true", dest="debug", default=False,
                     help="Enable debug message for the wx frontend.")
 
     options, args = parser.parse_args()
 
     app = wx.PySimpleApp()
     frame = IPythonX(None, wx.ID_ANY, 'IPythonX')
     frame.shell.debug = options.debug
     frame.shell.SetFocus()
     frame.shell.app = app
     frame.SetSize((680, 460))
 
     app.MainLoop()
 
 if __name__ == '__main__':
     main()