Bug report

Bug summary

The animation documentation states that the reference to the Animation object must be held to prevent the animation from stopping due to garbage collection. I cannot reproduce this. Also, I do not find any way to stop the animation. I presume the Animation object is held somewhere, and this is undocumented.

The bigger picture for me: I pass as the frames argument of FuncAnimation a generator which streams data from a device via a socket. When the generator is garbage collected, the socket is deleted and the device is free to take new connections. Because I cannot garbage collect the Animation object, I cannot garbe collec the socket instrument either and the device hangs.

Related #16221

Code for reproduction

Adapted from https://matplotlib.org/3.1.3/api/animation_api.html :

import numpy as np
import matplotlib
import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation
import gc
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,
FuncAnimation(fig, update, frames=np.linspace(0, 2*np.pi, 128),
 init_func=init, blit=True)
gc.collect() # force garbage collection
plt.show()

Actual outcome

The animation works.

Expected outcome

The animation should not work, as described in the doc.

Matplotlib version

• Operating system: Windows 10
• Matplotlib version: 3.1.3
• Matplotlib backend (print(matplotlib.get_backend())): issue affects at least Qt5Agg and Tk5Agg
• Python version: 3.7.6
• Jupyter version (if applicable):
• Other libraries: Anaconda 2020.02

Issue was reproducted in a Python console and in Spyder 4