A combobox can be created with the QComboBox class. Items are added using the class method addItem, followed by a string parameter.

A combobox is a dropdown list. The user clicks it and picks one item. In PyQt the class is QComboBox, and sometimes people call it a listbox.

Sometimes its called a listbox, as it shows a list of items a user can select from. If you want a user to choose from a set of items, the listbox is the best option.

Combobox example

In Python PyQt you can create a combobox with the widget QComboBox. This type of widget lets you select from a list of options. To use it, first import it from the PyQt module.

from PyQt5.QtWidgets import QComboBox

Then you can create one or more instances of the QComboBox.

self.comboBox = QComboBox(centralWidget)

Then you want to configure it, like changing the size and its position (x,y,width,height). You can do that with the method call setGeometry().

self.comboBox.setGeometry(QRect(40, 40, 491, 31))

And adding several items to the combo box, these items are shown when you click on the combobox. A combobox can have any number of items.

self.comboBox.addItem("Item 1")
self.comboBox.addItem("Item 2")
self.comboBox.addItem("Item 3")
pyqt combobox

The code below creates a combobox using the class QComboBox. The appearance of the combbox depends on the operating system you are using.

# https://pythonprogramminglanguage.com/pyqt-combobox/
import sys
from PyQt5 import QtCore, QtWidgets
from PyQt5.QtWidgets import QMainWindow, QLabel, QGridLayout, QWidget, QComboBox
from PyQt5.QtCore import QSize, QRect    

class ExampleWindow(QMainWindow):
    def __init__(self):
        QMainWindow.__init__(self)

        self.setMinimumSize(QSize(640, 140))    
        self.setWindowTitle("Combobox example") 

        centralWidget = QWidget(self)          
        self.setCentralWidget(centralWidget)   

        # Create combobox and add items.
        self.comboBox = QComboBox(centralWidget)
        self.comboBox.setGeometry(QRect(40, 40, 491, 31))
        self.comboBox.setObjectName(("comboBox"))
        self.comboBox.addItem("PyQt")
        self.comboBox.addItem("Qt")
        self.comboBox.addItem("Python")
        self.comboBox.addItem("Example")

if __name__ == "__main__":
    app = QtWidgets.QApplication(sys.argv)
    mainWin = ExampleWindow()
    mainWin.show()
    sys.exit( app.exec_() )

If you have a list of options or items you can use a for loop to add them.

options = ["Athens","Bruxelles","Chengmai","Dover"]
for option in options:
    self.comboBox.addItem(option)

Working with it

  • addItem('Python') adds one item.
  • addItems(['a', 'b']) adds a whole list.
  • setCurrentIndex(0) selects an item by position.
  • setCurrentText('Python') selects by text.
  • currentText() gives the selected text, currentIndex() the position.
  • count() gives the number of items.
  • currentIndexChanged and currentTextChanged are the signals.
  • setEditable(True) lets the user type a value that is not in the list.

With an editable combobox check currentText() and not currentIndex(), because a typed value has no index.

Want more practice on this? Practise this on PyChallenge, there are short browser exercises you can run right after reading.