參數1有意想不到的類型'NoneType'？

Question

我的PyQt按鈕操作出現問題。我想送一個字符串的功能，但我得到這個錯誤：

TypeError: argument 1 has unexpected type 'NoneType'

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_()) 

Answer 1

正如user3030010和ekhumoro，預計可調用的函數建議。在這種情況下，就應該更換這樣的說法與lambda: micCocktail("string") 和還不使用str它是一個python內置數據類型我有_str

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(lambda: micCocktail("string")) 

widget.show() 
sys.exit(app.exec_())