It doesn't really work - text didn't change - why it doesn't work? It doesn't give me any error (but print prints what it should)

I call function through keyboard event

Insert code in your post, do not give external unfunctioning links!

# a very simple template to test PyQT widgets
# PyQT free from:
# used Windows installer PyQt-Py3.2-x86-gpl-4.8.4-1.exe
# tested with PyQT 4.8 and Python 3.2

from PyQt4.QtCore import *
from PyQt4.QtGui import *

app = QApplication([])

# ----- start your widget test code ----

# create the label
label = QLabel()
# insert a text string
label.setText('hello all together')

# ---- end of widget test code -----


So sorry for mistake, i have already discover why it wasn't working, and deleted files from my dropbox folder, it's why it doesn't work. i just used class() instead variable = class(), class.ui.etc.etc.