Runnying PyQT5 app the 2nd time does not work

Question

I am trying to run a simple Hello world example. After running and closing the GUI window the first time, the code does not work the 2nd time. It appears that the previous instance is not complete. Any ideas what needs to be done to overcome this? (I am using Spyder)

from PyQt5.QtWidgets import *
app = QApplication([])
label = QLabel('Hello World!')
label.show()
app.exec_()

Answer 1

Try this ? I had a similar problem in a loop

app = QApplication.instance()
if app is None:
   app = QApplication([])

Answer 2

try this

from PyQt5.QtWidgets import QLabel, QApplication
import sys

app = QApplication([])
label = QLabel('Hello World!')
label.show()
sys.exit(app.exec_())