title: UI Application not loading PyQt5
body: <p>I don't know why this application doesn't load my ui. I've written the exact codes that I've found on the internet but didn't get any result.</p>
  
  <pre><code>from PyQt5.uic import loadUi
  from PyQt5.QtWidgets import QApplication, QMainWindow
  import sys
  
  
  class Receipt(QMainWindow):
  
      def __init__(self):
          super().__init__()
          self.ui = None
          self.load_ui()
          self.load_signals()
  
      def load_ui(self):
          self.ui = loadUi('window.ui')
          self.show()
  
      def load_signals(self):
          pass
  
  app = QApplication(sys.argv)
  receipt = Receipt()
  sys.exit(app.exec_()) 
  </code></pre>