Hi
Forgive me if I'm off the mark (its a late night here), but it seems that the wxpython / wxpython-dev packages for SliTaz 4.0 contain wxWidgets / wxWidgets-dev files instead. At least thats how it looks when comparing the file lists for these packages (via pkgs.slitaz.org) for SliTaz 4.0. They seem ok in Cooking.
Downloading, compiling and installing the full wxWidgets (inc wxPython) from src seemed to work ok for SliTaz 4.0, but I haven't tested it extensively. "Borrowing" the wxpython packages from SliTaz Cooking, as a workaround, also seemed to work for my needs, but thats probably not a good practice for stability.
This may be related to the "ImportError: No module named wx" python error some people have experienced... at least that was the symptom I encountered.