Segmentation fault (core dumped) QgsApplication

Question

import os, os.path,sys
from qgis.core import *
from qgis.gui import *
from PyQt4.QtGui import *
from PyQt4.QtCore import *
class MapExplorer(QMainWindow):
 def __init__(self):
 QMainWindow.__init__(self)
 self.setWindowTitle("Landmark Explorer")
 self.resize(800, 400)
def main():
 QgsApplication.setPrefixPath(os.environ['QGIS_PREFIX'], True)
 QgsApplication.initQgis()
 app = QApplication(sys.argv)
 window = MapExplorer()
 window.show()
 window.raise_()
 app.exec_()
 app.deleteLater()
 QgsApplication.exitQgis()
if __name__ =="__main__":
 main()

Then run this code and get:

Segmentation fault (core dumped)

What did I do wrong?

OpenSuse 42.2

Answer 1

You've got your initialisation the wrong way round. Try:

app = QgsApplication(sys.argv, True)
QgsApplication.setPrefixPath(os.environ['QGIS_PREFIX'], True)
QgsApplication.initQgis()

Note also the creation of a QgsApplication, not a QApplication.

You might still get a seg fault when the application exits because I don't think you've cleaned up properly, but my adjustment above should pop up your main window.

Answer 2

This worked:

app = QApplication(sys.argv)
QgsApplication.setPrefixPath(os.environ['QGIS_PREFIX'], True)
QgsApplication.initQgis()