text: #! /usr/bin/env python3
  
  import sys
  from PyQt5.QtCore import Qt
  from PyQt5.QtWidgets import QApplication, QWidget, QLabel, QHBoxLayout
  
  app = QApplication(sys.argv)
  window = QWidget()
  window.setWindowTitle("Label")
  layout = QHBoxLayout()
  window.setLayout(layout)
  label = QLabel("Hello, world!")
  label.setAlignment(Qt.AlignCenter)
  layout.addWidget(label)
  window.show()
  sys.exit(app.exec_())
  