[Tkinter-discuss] Inserting a unicode zero-width nonbreaking space into a Text widget, from Tkinter, on a Mac

[Jeff Epler]

In *theory*, 
    # t = Tkinter.Text()
    t.insert(Tkinter.END, u"a\ufeffb")
should work just fine.  However, I doubt Tk's text engine has enough
advanced text layout to respond appropriately to a zero-width
nonbreaking space.  (heck, I just learned my mozilla doesn't properly
render \u200b, a breaking zero-width space)

Anyway, Tk has some complicated machinery to look through a number of
operating system fonts in various encodings to find a font where the
encoding of the character maps onto an existing glyph.  When this fails,
it shows a placeholder (empty rectangle---what I got in my test, on
a Linux system) or an \xXXXX escape code.  If it shows an incorrect
character, I'd be tempted to blame either a font with a character
that u"\ufeff" (erroneously) encodes to, or a bad Tcl encoding that
(erroneously) encodes u'\ufeff' to the wrong thing.  It doesn't make
things easier that Tcl has its own encoding machinery and list of fonts
to try.

Jeff