Description
Bug report
Bug summary
I'm implementing live plotting for our data acquisition system using Jupyter and FuncAnimation, and have just found an interesting defect in plt.show(block=True) behaviour.
Precisely, it does not unblock when the plot window is closed, and sending KeyboardInterrupt crashes the kernel.
I was able to accidentally fix the first part by modifying the show() function in backend_bases.py based on this forum reply (basically, by not calling manager.canvas.figure.show() when block is not None, and instead callingmanager.window.setVisible(True) just before cls.mainloop() since it calls Qt's exec() that should call show() by itself)
The second issue persists, though.
Code for reproduction
%pylab qt5
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation
fig, ax = plt.subplots()
xdata, ydata = [], []
ln, = plt.plot([], [], 'ro')
def init():
ax.set_xlim(0, 2*np.pi)
ax.set_ylim(-1, 1)
return ln,
def update(frame):
xdata.append(frame)
ydata.append(np.sin(frame))
ln.set_data(xdata, ydata)
return ln,
ani = FuncAnimation(fig, update, frames=np.linspace(0, 2*np.pi, 128),
init_func=init, blit=True, interval = 50)
plt.show(block=True)Actual outcome
Plot window that can be closed by either pressing the corresponding window button or by sending KeyboardInterrupt. The kernel then should be freed.
Expected outcome
The kernel is not freed upon closing (without my fix) and dies on KeyboardInterrupt.
Matplotlib version
- Operating system: 4.18.16-100.fc27.x86_64
- Matplotlib version: 3.0.2
- Matplotlib backend: Qt5Agg
- Python version: 3.6
- IPython: 7.2.0
- Jupyter notebook: 5.7.4
Everything installed with pip in a virtualenv.