PyQt5 comes with a font dialog that you may have seen in a text editor. To open this dialog import QFontDialog call:

QFontDialog.getFont()

Font Dialog using PyQt5

Related course:
Practice Python with interactive exercises

PyQt5 font dialog The example below opens a font dialog on a button event, the selected font (font family including size) will be returned as a string.

import sys
from PyQt5.QtWidgets import QApplication, QWidget, QPushButton, QFontDialog
from PyQt5.QtGui import QIcon
from PyQt5.QtCore import pyqtSlot
class App(QWidget):
def __init__(self):
        super().__init__()
        self.title = 'PyQt5 font dialog - pythonspot.com'
        self.left = 10
        self.top = 10
        self.width = 320
        self.height = 200
        self.initUI()
    
    def initUI(self):
        self.setWindowTitle(self.title)
        self.setGeometry(self.left, self.top, self.width, self.height)
        
        button = QPushButton('Open PyQt5 Font Dialog', self)
        button.setToolTip('font dialog')
        button.move(50,50)
        button.clicked.connect(self.on_click)
        
        self.show()
    
    @pyqtSlot()
    def on_click(self):
        print('PyQt5 button click')
        openFontDialog(self)
    
    def openFontDialog(self):
        font, ok = QFontDialog.getFont()
    if ok:
        print(font.toString())
    
if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = App()
    sys.exit(app.exec_())