Use a QButtonGroup:
self.buttonGroup = QtGui.QButtonGroup(self)
self.buttonGroup.buttonClicked[int].connect(self.getArchive)
for row, dossier in enumerate(Dossier.listeDossiers):
button = QPushButton("Archive")
self.buttonGroup.addButton(button, row)
self.dlg.ui.tableWidget_dossiers.setCellWidget(row, 5, button)
def getArchive(self, row):
print "Row " + str(row)