Undefined variable from import when using wxPython in pydev

Question

I just downloaded wxPython, and was running some of the sample programs from here. However, on every line that uses a variable from wx.*, I get a "Undefined variable from import error"

For example, the following program generates five errors on lines 1,4,8, and two on line 5:

import wx
class MyFrame(wx.Frame):
    """ We simply derive a new class of Frame. """
    def __init__(self, parent, title):
        wx.Frame.__init__(self, parent, title=title, size=(200,100))
        self.control = wx.TextCtrl(self, style=wx.TE_MULTILINE)
        self.Show(True)
app = wx.App(False)
frame = MyFrame(None, 'Small editor')
app.MainLoop()

The program, however, compiles and runs perfectly. I haven't made any significant modifications to pydev or eclipse, and the wxPython install is fresh.

Answer 1

This happened to me. I had installed PyDev and configured it and went on my merry way. A few months later, I installed wxPython and had this same problem. An easy way to fix is in eclipse:

Window -> Preferences -> Pydev -> Interpreter - Python

Just remove the default interpreter and add a new one (it can be the same one you had before). Pydev/Eclipse searches through your Python Installation directory and adds the correct paths to your PYTHONPATH. I restarted and all was well. I noticed it added

C:\Python26\lib\site-packages\wx-2.8-msw-unicode

So you could probably just add that to the PYTHONPATH instead of going through all the above, assuming that path is where this directory is installed.

By the way, I am using:

1. Eclipse Helios
2. Pydev 1.6.2.2010090812
3. Python 2.6
4. wxPython2.8-win32-unicode-2.8.11.0-py26

But I think this should be a pretty general solution to the problem.

Answer 2

PyDev finds the references when you setup the interpreter in

Window -> Preferences -> Pydev -> Interpreter - Python

If wxPython was not in your site-packages directory when you first setup the interpreter, then the references to the wx objects and names will not be known to the editor lookup function. To fix this, remove the interpreter from

Window -> Preferences -> Pydev -> Interpreter - Python

and then select new. Re-add the python installation again and press apply. At this time, Pydev will import all of the site-package objects again and should populate the lookup dictionary. You'll want to restart Eclipse for changes to take place.