[qt5] font dialog

font_dialog.py

import sys
from PyQt5.QtWidgets import (QWidget, QVBoxLayout, QPushButton,
                             QSizePolicy, QLabel, QFontDialog, QApplication)


class Example(QWidget):
    def __init__(self):
        super().__init__()
        self.init_ui()

    def init_ui(self):
        v_box = QVBoxLayout()

        btn = QPushButton('Dialog', self)
        btn.setSizePolicy(QSizePolicy.Fixed,
                       QSizePolicy.Fixed)

        btn.move(20, 20)

        v_box.addWidget(btn)

        btn.clicked.connect(self.show_dialog)

        self.lbl = QLabel('Knowledge only matters', self)
        self.lbl.move(130, 20)

        v_box.addWidget(self.lbl)
        self.setLayout(v_box)

        self.setGeometry(300, 300, 250, 180)
        self.setWindowTitle('Font dialog')
        self.show()

    def show_dialog(self):
        font, ok = QFontDialog.getFont()
        if ok:
            self.lbl.setFont(font)


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