GTK+ uses UTF-8 encoded strings for all text. This means that if you call a method that returns a string you will always obtain an instance of the str type. The same applies to methods that expect one or more strings as parameter, they must be UTF-8 encoded. However, for convenience PyGObject will automatically convert any unicode instance to str if supplied as argument:

>>> from gi.repository import Gtk

>>> label = Gtk.Label()

>>> unicode_string = u"Fu\u00dfb\u00e4lle"

>>> label.set_text(unicode_string)

>>> txt = label.get_text()

>>> type(txt), txt

(<type 'str'>, 'Fu\xc3\x9fb\xc3\xa4lle')

>>> txt == unicode_string

__main__:1: UnicodeWarning: Unicode equal comparison failed to convert

both arguments to Unicode - interpreting them as being unequal

False

Note the warning at the end. Although we called Gtk.Label.set_text() with a unicode instance as argument, Gtk.Label.get_text() will always return a str instance. Accordingly, txt and unicode_string are not equal.

This is especially important if you want to internationalize your program using gettext. You have to make sure that gettext will return UTF-8 encoded 8-bit strings for all languages. In general it is recommended to not use unicode objects in GTK+ applications at all and only use UTF-8 encoded str objects since GTK+ does not fully integrate with unicode objects. Otherwise, you would have to decode the return values to Unicode strings each time you call a GTK+ method:

>>> txt = label.get_text().decode("utf-8")

>>> txt == unicode_string

True