maya_standalone_GUI_test.py

import sys
from PySide2.QtWidgets import *
import maya.standalone as ms
import maya.cmds as mc

class Window(QWidget):
    def __init__(self):
        super(Window, self).__init__()
        self.setupUI()
        self.show()

    def setupUI(self):
        self.layout = QHBoxLayout()
        self.setLayout(self.layout)
        self.button = QPushButton("List Scene")
        self.button_create = QPushButton("Create Node")
        self.layout.addWidget(self.button)
        self.layout.addWidget(self.button_create)

        self.button.clicked.connect(self.list_scene)
        self.button_create.clicked.connect(self.create_node)

    def list_scene(self):
        print mc.ls(type='transform')

    def create_node(self):
        print mc.group(em=True)


if __name__ == '__main__':
    app = QApplication(sys.argv)
    ms.initialize()
    win = Window()
    app.exec_()