PyQt4 核心转储答案

【问题标题】：Core dump with PyQt4PyQt4 核心转储
【发布时间】：2013-08-24 07:34:11
【问题描述】：

我从 PyQt4 开始，在最简单的示例中使用 QGraphicsScene/View 时面临核心转储：

#!/usr/bin/python

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *

app = QApplication(sys.argv)

grview = QGraphicsView()
scene = QGraphicsScene()
grview.setScene(scene)

grview.show()

sys.exit(app.exec_())

程序运行，但在关闭时会出现大量 GTK 错误（使用 Ubuntu），最后是核心转储（分段错误）：

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_container_add: assertion `GTK_IS_CONTAINER (container)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed

(python:2732): Gtk-CRITICAL **: IA__gtk_widget_realize: assertion `GTK_WIDGET_ANCHORED (widget) || GTK_IS_INVISIBLE (widget)' failed
Violación de segmento (`core' generado)

我认为这与我的 linux 设置有关。有人遇到过这种情况吗？

谢谢！

【问题讨论】：

标签： ubuntu pyqt4

【解决方案1】：

GTK 错误可能与段错误无关。我正在使用 KDE（因此不是 gtk 主题），所以我没有看到任何 GTK 错误，但我确实遇到了段错误。

段错误发生在QGraphicsScene的析构函数中：

#0  0x00007ffff6f09037 in raise () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007ffff6f0c698 in abort () from /lib/x86_64-linux-gnu/libc.so.6
#2  0x00007ffff5b465c2 in qt_message_output(QtMsgType, char const*) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#3  0x00007ffff5b46938 in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#4  0x00007ffff5b46ac4 in qFatal(char const*, ...) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#5  0x00007ffff389231e in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#6  0x00007ffff3893401 in QPixmap::QPixmap() () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#7  0x00007fffea0a8c86 in Oxygen::Helper::Helper(QByteArray const&) () from /usr/lib/liboxygenstyle.so.4
#8  0x00007fffea3450e0 in ?? () from /usr/lib/kde4/plugins/styles/oxygen.so
#9  0x00007fffea32f757 in ?? () from /usr/lib/kde4/plugins/styles/oxygen.so
#10 0x00007fffea33c7bc in ?? () from /usr/lib/kde4/plugins/styles/oxygen.so
#11 0x00007ffff3ab64e6 in QStyleFactory::create(QString const&) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#12 0x00007ffff37c74cf in QApplication::style() () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#13 0x00007ffff37fe488 in QWidget::isActiveWindow() const () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#14 0x00007ffff3dd5ccc in QGraphicsView::setScene(QGraphicsScene*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#15 0x00007ffff3da47d1 in QGraphicsScene::~QGraphicsScene() () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#16 0x00007ffff46b6bb9 in ?? () from /usr/lib/python2.7/dist-packages/PyQt4/QtGui.so
#17 0x00007ffff46b4ad6 in ?? () from /usr/lib/python2.7/dist-packages/PyQt4/QtGui.so
#18 0x00007ffff4c6115e in ?? () from /usr/lib/python2.7/dist-packages/sip.so
#19 0x00007ffff4c62aa9 in ?? () from /usr/lib/python2.7/dist-packages/sip.so
#20 0x00000000004af4f0 in ?? ()
#21 0x00000000004dbbc7 in ?? ()
#22 0x00007ffff4c6058b in ?? () from /usr/lib/python2.7/dist-packages/sip.so
#23 0x00007ffff4c62a22 in ?? () from /usr/lib/python2.7/dist-packages/sip.so
#24 0x00007ffff4c62ab1 in ?? () from /usr/lib/python2.7/dist-packages/sip.so
#25 0x00000000004af4f0 in ?? ()
#26 0x00000000004b8bca in ?? ()
#27 0x00000000004a4460 in PyDict_SetItem ()
#28 0x00000000004a46d7 in _PyModule_Clear ()
#29 0x0000000000509514 in PyImport_Cleanup ()
#30 0x0000000000423bca in Py_Finalize ()
#31 0x0000000000424470 in Py_Exit ()
#32 0x00000000004245ac in ?? ()
#33 0x000000000042254e in PyErr_PrintEx ()
#34 0x0000000000465e0d in PyRun_SimpleFileExFlags ()
#35 0x0000000000466b78 in Py_Main ()
#36 0x00007ffff6ef3ea5 in __libc_start_main () from /lib/x86_64-linux-gnu/libc.so.6
#37 0x00000000004e0d95 in _start ()

将grview 设为scene 的父级应该可以解决这个问题：

#!/usr/bin/python

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *

app = QApplication(sys.argv)

grview = QGraphicsView()
scene = QGraphicsScene(grview)

grview.setScene(scene)

grview.show()

sys.exit(app.exec_())

QObjects 构造的没有父级是owned by PyQt and not by Qt，这个错误可能是析构函数在退出时被调用两次的结果。

【讨论】：

成功了。但我不明白为什么它失败了。为什么 setScene 调用不够？无论如何，很好的答案。我接受它并结束这个问题。谢谢！
我只能推测当 QGraphicsView 被销毁时在 Qt 端调用了析构函数，并且当 scene 为 garbage collected 时 PyQt 也会调用它 - 但我真的不能说出哪个先发生。
最后一句可能应该是“QObject 构造 with parent 由 Qt 而不是 PyQt 拥有”，因为 doc 声明“父参数，如果不是 None，导致self被Qt而不是PyQt拥有”？
编辑后的版本现在很好，和文档的版本一样，谢谢。
@mata It does work in pyqt4, but not pyqt5.