Change QLabel text dynamically in PyQt4

StackOverflow https://stackoverflow.com/questions/19985640

Question

My question is: how can I change the text in a label? The label is inside a layout, but setText() does not seem to work - maybe I am not doing it right.

Here is my code:

this is the Main windows GUI, the one Qt-Designer gives:

class Ui_dashboard(QtGui.QMainWindow):
def setupUi(self, dashboard):
    dashboard.setObjectName(_fromUtf8("dashboard"))
    dashboard.resize(734, 703)
    icon = QtGui.QIcon()
    icon.addPixmap(QtGui.QPixmap(_fromUtf8("../../../../Documents and Settings/cgarcia/Escritorio/metromara - imagenes - nerio/logoM.JPG")), QtGui.QIcon.Normal, QtGui.QIcon.Off)
    dashboard.setWindowIcon(icon)
    dashboard.setWindowOpacity(1.0)
    self.centralwidget = QtGui.QWidget(dashboard)
    self.centralwidget.setObjectName(_fromUtf8("centralwidget"))
    self.frame = QtGui.QFrame(self.centralwidget)
    self.frame.setGeometry(QtCore.QRect(30, 20, 261, 119))
    self.frame.setFrameShape(QtGui.QFrame.Box)
    self.frame.setFrameShadow(QtGui.QFrame.Plain)
    self.frame.setObjectName(_fromUtf8("frame"))
    self.gridLayout = QtGui.QGridLayout(self.frame)
    self.gridLayout.setObjectName(_fromUtf8("gridLayout"))
    self.label_5 = QtGui.QLabel(self.frame)
    font = QtGui.QFont()
    font.setBold(True)
    font.setWeight(75)
    self.label_5.setFont(font)
    self.label_5.setObjectName(_fromUtf8("label_5"))
    self.gridLayout.addWidget(self.label_5, 4, 0, 1, 1)
    self.label_4 = QtGui.QLabel(self.frame)
    font = QtGui.QFont()
    font.setBold(True)
    font.setWeight(75)
    self.label_4.setFont(font)
    self.label_4.setObjectName(_fromUtf8("label_4"))
    self.gridLayout.addWidget(self.label_4, 3, 0, 1, 1)
    self.label_ci = QtGui.QLabel(self.frame)
    font = QtGui.QFont()
    font.setBold(True)
    font.setWeight(75)
    self.label_ci.setFont(font)
    self.label_ci.setObjectName(_fromUtf8("label_ci"))
    self.gridLayout.addWidget(self.label_ci, 1, 1, 1, 1)
    self.label_cargo = QtGui.QLabel(self.frame)
    font = QtGui.QFont()
    font.setBold(True)
    font.setWeight(75)
    self.label_cargo.setFont(font)
    self.label_cargo.setObjectName(_fromUtf8("label_cargo"))
    self.gridLayout.addWidget(self.label_cargo, 2, 1, 1, 1)
    self.label_gerencia = QtGui.QLabel(self.frame)
    font = QtGui.QFont()
    font.setBold(True)
    font.setWeight(75)
    self.label_gerencia.setFont(font)
    self.label_gerencia.setObjectName(_fromUtf8("label_gerencia"))
    self.gridLayout.addWidget(self.label_gerencia, 3, 1, 1, 1)
    self.label_nombre = QtGui.QLabel(self.frame)
    font = QtGui.QFont()
    font.setBold(True)
    font.setWeight(75)
    self.label_nombre.setFont(font)
    self.label_nombre.setObjectName(_fromUtf8("label_nombre"))
    self.gridLayout.addWidget(self.label_nombre, 0, 1, 1, 1)
    self.label_2 = QtGui.QLabel(self.frame)
    font = QtGui.QFont()
    font.setBold(True)
    font.setWeight(75)
    self.label_2.setFont(font)
    self.label_2.setObjectName(_fromUtf8("label_2"))
    self.gridLayout.addWidget(self.label_2, 1, 0, 1, 1)
    self.label = QtGui.QLabel(self.frame)
    font = QtGui.QFont()
    font.setBold(True)
    font.setWeight(75)
    self.label.setFont(font)
    self.label.setObjectName(_fromUtf8("label"))
    self.gridLayout.addWidget(self.label, 0, 0, 1, 1)
    self.label_3 = QtGui.QLabel(self.frame)
    font = QtGui.QFont()
    font.setBold(True)
    font.setWeight(75)
    self.label_3.setFont(font)
    self.label_3.setObjectName(_fromUtf8("label_3"))
    self.gridLayout.addWidget(self.label_3, 2, 0, 1, 1)
    self.label_departamento = QtGui.QLabel(self.frame)
    font = QtGui.QFont()
    font.setBold(True)
    font.setWeight(75)
    self.label_departamento.setFont(font)
    self.label_departamento.setObjectName(_fromUtf8("label_departamento"))
    self.gridLayout.addWidget(self.label_departamento, 4, 1, 1, 1)
    self.treeView = QtGui.QTreeView(self.centralwidget)
    self.treeView.setGeometry(QtCore.QRect(30, 160, 161, 481))
    self.treeView.setFrameShape(QtGui.QFrame.Box)
    self.treeView.setFrameShadow(QtGui.QFrame.Plain)
    self.treeView.setObjectName(_fromUtf8("treeView"))
    dashboard.setCentralWidget(self.centralwidget)
    self.menubar = QtGui.QMenuBar(dashboard)
    self.menubar.setGeometry(QtCore.QRect(0, 0, 734, 20))
    self.menubar.setObjectName(_fromUtf8("menubar"))
    dashboard.setMenuBar(self.menubar)
    self.statusbar = QtGui.QStatusBar(dashboard)
    self.statusbar.setObjectName(_fromUtf8("statusbar"))
    dashboard.setStatusBar(self.statusbar)

    self.retranslateUi(dashboard)
    QtCore.QMetaObject.connectSlotsByName(dashboard)

def retranslateUi(self, dashboard):
    dashboard.setWindowTitle(_translate("dashboard", "Metro de Maracaibo.", None))
    self.label_5.setText(_translate("dashboard", "DEPARTAMENTO", None))
    self.label_4.setText(_translate("dashboard", "GERENCIA", None))
    self.label_ci.setText(_translate("dashboard", "...", None))
    self.label_cargo.setText(_translate("dashboard", "...", None))
    self.label_gerencia.setText(_translate("dashboard", "...", None))
    self.label_nombre.setText(_translate("dashboard", "...", None))
    self.label_2.setText(_translate("dashboard", "C.I.:", None))
    self.label.setText(_translate("dashboard", "NOMBRE", None))
    self.label_3.setText(_translate("dashboard", "CARGO", None))
    self.label_departamento.setText(_translate("dashboard", "...", None))

this is the logic of the interfaces:

class logica_login(Ui_Dialog):
def __init__(self):
    QtGui.QDialog.__init__(self)
    #QtGui.QMainWindow.__init__(self)
    Dialog = Ui_Dialog(self)
    self.setupUi(Dialog)
    self.bloguin_aceptar.clicked.connect(self.validacion)
    self.blogin_cancelar.clicked.connect(self.reject)
    Dialog.show()
    Dialog.exec_()
    #PRINT DE PRUEBA
    print('hola')

#METODO DE VALIDACION
#####################
def validacion(self):
    #CONEXION A LA BASE DE DATOS.
    #############################
    db = QSqlDatabase.addDatabase("QPSQL")
    db.setHostName("localhost")
    db.setDatabaseName("postgres")
    db.setUserName("postgres")
    db.setPassword("1234")
    #self.ui.label_nombre.setText(str(Ui_Dialog.le_user.text()))

    #RESPUESTA EN CASO DE FALLO EN CONEXION CON LA BASE DE DATOS.
    #############################################################
    if not db.open():
        QtGui.QMessageBox.about(self, "ERROR","LO SENTIMOS, EXPERIMENTAMOS PROBLEMAS DE CONEXION CON EL SERVIDOR.")

    #CONSULTA A LA BASE DE DATOS DE LA CLAVE Y CONTRASEÑA
    #####################################################
    consulta = QSqlQueryModel()
    consulta.setQuery("SELECT usuario, contraseña, id FROM usuarios")
    lista = []
    i = consulta.rowCount()

    #BUCLE DE EXTRACCION Y REORDENACION DE DATOS EN LA LISTA "LISTA"
    ################################################################
    while i >= 0:
        db_user = consulta.record(i).value("usuario");
        db_pass = consulta.record(i).value("contraseña");
        db_id = consulta.record(i).value("id")
        str_user = str(db_user)
        str_pass = str(db_pass)
        auth_db = (str_user, str_pass)
        lista.append(auth_db)

        i = (i-1)
        print(lista)

    user = self.le_user.text()
    passw = self.le_pass.text()



    for usrname, password in lista:
        if ((user == usrname) and (passw == password)):
            print('logueo exitoso')
            QtGui.QMessageBox.about(self, "Logue Exitoso.", "ACCESO CONCEDIDO.")
            self.deleteLater()
            go = True
            print(go)
            dashboard.showMaximized()
            #self.ui.label_nombre.setText(str(Ui_Dialog.le_user.text())) ### LOGICA_LOGIN NO TIENE ATRIBUTO UI
            break;
        elif ((user == usrname) and (passw != password)):
            QtGui.QMessageBox.about(self, "ERROR","Contraseña Incorrecta.")
            break;
        elif ((user != usrname) and (passw == password)):
            QtGui.QMessageBox.about(self, "ERROR","Nombre de usuario Incorrecto")
            break;
    else:
        QtGui.QMessageBox.about(self, "ERROR","Nombre de usuario y Contraseña Incorrecto")


class logica_tablero(Ui_dashboard):

def __init__(self):
    l_n = Ui_dashboard.label_nombre()
    QtGui.QMainWindow.__init__(self)
    self.ui = Ui_dashboard(self)
    self.ui.setupUi(self)
    #logica_tablero.ui.l_n.setText("hola")
    Ui_dashboard.label_5.setText(("hola"))



def main():
    app = QtGui.QApplication(sys.argv)
    if 1 == 1 :
        loginApp = logica_login()
        loginApp.show()
    else:
        mainApp = Ui_dashboard()
        mainApp.setupUi(dash)
        dash.showMaximized()
        #Ui_dashboard.label_nombre.setText(("hola"))

    sys.exit(app.exec_())

if __name__ == "__main__":
    app = QtGui.QApplication(sys.argv)
    ## ESTA PARTE HA SIDO UN DOLOR DE CABEZA, NO OLVIDAR NI BORRAR.
    #BUCLE DE DASHBOARD
    #---------------------------------
    dashboard = QtGui.QMainWindow()
    mainApp = Ui_dashboard()
    mainApp.setupUi(dashboard)
    #BUCLE DE LOGIN
    #---------------------------------
    l = logica_login()
    l   
    #---------------------------------
    sys.exit(app.exec_())

I want to change the labels once the user logs in to the program. The label I want to change is label_nombre, and I want to replace it for le_user, which corresponds to one of the QLineEdits.

UPDATE

I made all the changes you told me to do, the project is looking pretty much organized, but now i am getting this output:

TypeError: descriptor 'init' requires a 'sip.simplewrapper' object but received a 'logica_login'

UPDATE 2

*TypeError: descriptor 'init' requires a 'sip.simplewrapper' object but received a 'logica_login' -------------------------> SOLVE

Now, I have the same problem that began this all deal, the label wont change its content.

Was it helpful?

Solution

You are not using the modules created by pyuic correctly. You should never directly edit these modules - they should imported into your main application.

The UI classes that pyuic generates have a setupUi method. This method takes an instance of the top-level class that you created in Qt Designer, and it will add all the widgets from designer to that instance. So label_nombre, for example, would become an attribute of the instance passed to setupUi. Usually, you will create a subclass of the top-level class, and then pass in self as the instance (see below).

I would suggest that you re-generate your ui files with pyuic and save them as, say dialog_ui.py and dashboard_ui.py.

The structure of your program would then become something like this:

from PyQt4 import QtCore, QtGui
from dashboard_ui import Ui_dashboard
from dialog_ui import Ui_Dialog

class logica_login(QtGui.QDialog, Ui_Dialog):
    def __init__(self):
        QtGui.QDialog.__init__(self)
        self.setupUi(self)
        self.bloguin_aceptar.clicked.connect(self.validacion)
        self.blogin_cancelar.clicked.connect(self.reject)

    def validacion(self):
        ...

class logica_tablero(QtGui.QMainWindow, Ui_dashboard):
    def __init__(self):
        QtGui.QMainWindow.__init__(self)
        self.setupUi(self)
        self.label_nombre.setText("hola")
        ...

if __name__ == "__main__":

    app = QtGui.QApplication(sys.argv)
    login = logica_login()
    if login.exec_() == QtGui.QDialog.Accepted:
        dashboard = logica_tablero()
        dashboard.showMaximized()
        sys.exit(app.exec_())

OTHER TIPS

Replace this line in logica_tablero:

self.ui.self.label_nombre.setText("hola")

with this:

self.ui.label_nombre.setText("hola")
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