使用qt4agg运行matplotlib后关闭时，Python脚本由于导入而崩溃

Question

I have written a script using matplotlib, which runs just fine with the standard matplotlib. The script is written with the plot as a class, and calling Plot() is enough to get it running.

Now I want to add some buttons to the toolbar, and to do this I am using qt4agg because I have installed matplotlib via Anaconda. When writing the code for the main window I used this example, and it runs just fine. In order to use the plot script I have already written I want to pass the figure created in the QT-script to the Plot()-class.

This solution works just fine, until I try to close the window. The window closes, and python crashes. It crashes even though I do not call the Plot()-class, and the only way to get it to not crash is to remove the line importing the file. Is there something special I need to think about when importing a script into a window?

from __future__ import print_function
import sys
from matplotlib.figure import Figure
from matplotlib.backend_bases import key_press_handler
### LINE CAUSING TROUBLE
from plotting import Plot
###
from test import *
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt4agg import NavigationToolbar2QT as NavigationToolbar
from matplotlib.backends import qt_compat
use_pyside = qt_compat.QT_API == qt_compat.QT_API_PYSIDE

if use_pyside:
    print ("USING PYSIDE")
    from PySide.QtCore import *
    from PySide.QtGui import *
else:
    print("NOT USING PYSIDE")
    from PyQt4.QtCore import *
    from PyQt4.QtGui import *

class AppForm(QMainWindow):
    def __init__(self, parent=None):
        QMainWindow.__init__(self, parent)
        self.create_main_frame()
        self.on_draw()

    def create_main_frame(self):
        self.main_frame = QWidget()

        self.fig = Figure()
        self.canvas = FigureCanvas(self.fig)
        self.canvas.setParent(self.main_frame)
        self.canvas.setFocusPolicy(Qt.StrongFocus)
        self.canvas.setFocus()

        self.mpl_toolbar = NavigationToolbar(self.canvas, self.main_frame)

        self.canvas.mpl_connect('key_press_event', self.on_key_press)

        vbox = QVBoxLayout()
        vbox.addWidget(self.canvas)
        vbox.addWidget(self.mpl_toolbar)
        self.main_frame.setLayout(vbox)
        self.setCentralWidget(self.main_frame)

    def on_draw(self):
        self.fig.clear()
        #Plot(self.fig)
        self.canvas.draw()

    def on_key_press(self, event):
        key_press_handler(event, self.canvas, self.mpl_toolbar)

def main():
    app = QApplication(sys.argv)
    form = AppForm()
    form.show()
    app.exec_()

if __name__ == "__main__":
    main()

Here is a very compressed version of the other file that still causes the error.

import matplotlib.pyplot as pplt

class Plot():
    def __init__(self, figure=pplt.figure()):
        self.figure = figure

Answer 1

i had the same problems with Anaconda and Python(x,y) . then i tried to install Python from scratch :

1. python-2.7.10.msi
2. PyQt4-4.11.4-gpl-Py2.7-Qt4.8.7-x32.exe
3. VCForPython27.msi
4. pip install matplotlib

it doesn't solve all crashes. you could also try this :

self.setAttribute(Qt.WA_DeleteOnClose)

for example :

class AppForm(QMainWindow):
    def __init__(self, parent=None):
        QMainWindow.__init__(self, parent)
        self.setAttribute(Qt.WA_DeleteOnClose) # <---
        self.create_main_frame()
        self.on_draw()
...