你能在Python中捕获PyQt5“快速失败异常”吗？

Question

通常，如果您在 PyQt5 对象上调用不存在的方法，例如在布尔变量上调用

.show()

，如下面的单击处理程序所示，这是一个始终会触发异常的示例：

import sys, os
from PyQt5.QtWidgets import QApplication, QMainWindow, QPushButton

class MainWindow(QMainWindow):
  def __init__(self):
    super().__init__()
    print("Hello from MainWindow")
    self.setWindowTitle("My App")
    button = QPushButton("Press me!")
    button.clicked.connect(self.button_clicked)
    self.setCentralWidget(button)
  def button_clicked(self, s):
    print("click", s)
    s.show()

def main(argv=None):
  app = QApplication(sys.argv)
  window = MainWindow()
  window.show()
  try:
    app.exec()
  except:
    print("Exception")

if __name__ == '__main__':
    main()

因此，当我单击此示例中的按钮时，我得到：

---------------------------
My App: python3.exe - Fail Fast Exception
---------------------------
A fail fast exception occurred. Exception handlers will not be invoked and the process will be terminated immediately. 
---------------------------
OK   
---------------------------

好的 - 但如果我将

app.exec()

包装在

try ... catch

块中，- 显然，- 它不会捕获此异常（可能是因为它来自 C++ PyQt5 对象）？

所以，我的问题是：我能以某种方式捕获/处理Python中的这种异常吗（但希望在“链下”的某个地方，就像尝试用一条语句捕获任何此类应用程序异常一样，正如我尝试过的那样）与

try ... catch

周围的

app.exec()

相关）吗？

Answer 1

尝试一下：

import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, \
    QPushButton, QMessageBox
    

class MainWindow(QMainWindow):
  def __init__(self):
    super().__init__()
    print("\nHello from MainWindow")
    self.setWindowTitle("My App")
    
    button = QPushButton("Press me!")
    button.clicked.connect(self.button_clicked)
    self.setCentralWidget(button)
    
  def button_clicked(self, checked):
    print(f"\nbutton checked: {checked}\n")
    checked.show()

# +++ vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
import traceback
def except_hook(exc_type, exc_value, exc_tb):
    tb = "".join(traceback.format_exception(exc_type, exc_value, exc_tb))
    msg = QMessageBox.warning(
        None, 
        'Attention! ERROR!', 
        f'{tb}' 
    )        
# +++ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

if __name__ == '__main__':
    app = QApplication(sys.argv)
  
    sys.excepthook = except_hook                              # +++ <----
      
    window = MainWindow()
    window.show()
    exit(app.exec())