title: Argument 1 has unexpected type 'NoneType'?
body: <p>I have a problem with my PyQt button action. I would like to send a String with the Function but I got this Error:</p>
  
  <blockquote>
    <p>TypeError: argument 1 has unexpected type 'NoneType'</p>
  </blockquote>
  
  <pre><code>import sys
  
  from PyQt5.QtWidgets import QApplication, QPushButton, QAction
  from PyQt5.QtCore import QObject, pyqtSignal
  from PyQt5.QtGui import *
  from PyQt5.uic import *
  
  app = QApplication(sys.argv)
  cocktail = loadUi('create.ui')
  
  def mixCocktail(str):
        cocktail.show()
        cocktail.showFullScreen()
        cocktail.lbl_header.setText(str)
  
  
  widget = loadUi('drinkmixer.ui')
  
  widget.btn_ckt1.clicked.connect(mixCocktail("string"))
  
  widget.show()
  sys.exit(app.exec_())
  </code></pre>