testUI.py

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, QLabel, QComboBox, QPushButton


class Example(QMainWindow):

    def __init__(self):
        super().__init__()

        combo = QComboBox(self)
        combo.addItem("Apple")
        combo.addItem("Pear")
        combo.addItem("Lemon")
        combo.setEditable(True)
        combo.move(50, 50)

        self.qlabel = QLabel(self)
        self.qlabel.move(50, 16)

        combo.activated[str].connect(self.onChanged)

        self.setGeometry(50, 50, 320, 200)
        self.setWindowTitle("QLineEdit Example")
        self.show()

    def onChanged(self, text):
        self.qlabel.setText(text)
        self.qlabel.adjustSize()


if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())

'''
#!/usr/bin/env python
# -*- coding: utf-8 -*-
from PyQt5.QtCore import Qt, QSortFilterProxyModel
from PyQt5.QtWidgets import QComboBox, QCompleter, QApplication
from numpy import unicode


class ExtendedComboBox(QComboBox):
    def __init__(self, parent=None):
        super(ExtendedComboBox, self).__init__(parent)

        self.setFocusPolicy(Qt.StrongFocus)
        self.setEditable(True)

        # add a filter model to filter matching items
        self.pFilterModel = QSortFilterProxyModel(self)
        self.pFilterModel.setFilterCaseSensitivity(Qt.CaseInsensitive)
        self.pFilterModel.setSourceModel(self.model())

        # add a completer, which uses the filter model
        self.completer = QCompleter(self.pFilterModel, self)
        # always show all (filtered) completions
        self.completer.setCompletionMode(QCompleter.UnfilteredPopupCompletion)
        self.setCompleter(self.completer)

        # connect signals
        self.lineEdit().textEdited[unicode].connect(self.pFilterModel.setFilterFixedString)
        self.completer.activated.connect(self.on_completer_activated)

    # on selection of an item from the completer, select the corresponding item from combobox
    def on_completer_activated(self, text):
        if text:
            index = self.findText(text)
            self.setCurrentIndex(index)

    # on model change, update the models of the filter and completer as well
    def setModel(self, model):
        super(ExtendedComboBox, self).setModel(model)
        self.pFilterModel.setSourceModel(model)
        self.completer.setModel(self.pFilterModel)

    # on model column change, update the model column of the filter and completer as well
    def setModelColumn(self, column):
        self.completer.setCompletionColumn(column)
        self.pFilterModel.setFilterKeyColumn(column)
        super(ExtendedComboBox, self).setModelColumn(column)


if __name__ == "__main__":
    import sys

    app = QApplication(sys.argv)

    string_list = ['hola muchachos', 'adios amigos', 'hello world', 'good bye']

    combo = ExtendedComboBox()

    # either fill the standard model of the combobox
    combo.addItems(string_list)

    # or use another model
    # combo.setModel(QStringListModel(string_list))

    combo.resize(300, 40)
    combo.show()

'''