import sys
from PySide2 import QtCore
from PySide2.QtGui import QStandardItemModel, QStandardItem
from PySide2.QtWidgets import QApplication, QWidget, QPushButton, QListView, QLineEdit
from PySide2.QtUiTools import QUiLoader

def form():
    def item_changed(item):
        print("New value {} at index {}".format(item.text(), item.row()))

    def item_select(index):
        item = model.itemFromIndex(index)
        print("Selected {} at index {}".format(item.text(), item.row()))
        form.edit.setText = "Selected {} at index {}".format(item.text(), item.row())

    form = QUiLoader().load("form.ui")
    form.resize(100, 200)
    form.setWindowModality(QtCore.Qt.ApplicationModal)

    form.label.setText("Выбирай что хочешь")

    model = QStandardItemModel()

    for name in ["Pascal", "PHP", "Python"]:
        item = QStandardItem(name)
        model.appendRow(item)

    form.list.setModel(model)

    model.itemChanged.connect(item_changed)
    form.list.clicked.connect(item_select)

    return form

app = QApplication(sys.argv)

window = QWidget()
window.resize(400, 300)

form = form()

button = QPushButton("Open Form", window)
button.setToolTip("Click here and you'll see")
button.setGeometry(150, 130, 100, 30)
button.clicked.connect(lambda: form.show())

window.show()

sys.exit(app.exec_())