python - 值错误 : I/O operation on closed file with ffmpeg

Question

我试图让这个( minimal working example )代码在我在 super 计算集群中设置的 Anaconda 上的虚拟环境中编译:

import numpy as np
import matplotlib
matplotlib.use("Agg")
import matplotlib.pyplot as plt
import matplotlib.animation as manimation

FFMpegWriter = manimation.writers['ffmpeg']
metadata = dict(title='Movie Test', artist='Matplotlib',
            comment='Movie support!')
writer = FFMpegWriter(fps=15, metadata=metadata)

fig = plt.figure()
l, = plt.plot([], [], 'k-o')

plt.xlim(-5, 5)
plt.ylim(-5, 5)

x0, y0 = 0, 0

with writer.saving(fig, "writer_test.mp4", 100):
    for i in range(100):
        x0 += 0.1 * np.random.randn()
        y0 += 0.1 * np.random.randn()
        l.set_data(x0, y0)
        writer.grab_frame()

问题是，此代码 在我的本地机器上工作得很好 (MacOSX) - Anaconda 发行版； python 2.7；相同的 matplotlib 和 numpy 版本，我在 Anaconda 上有 ffmpeg；我在集群上也有 ffmpeg，尽管版本与 Python 上的版本不同(但在我的本地机器上没有问题)。当我在 上运行代码时集群 ，我得到:

Traceback (most recent call last):
  File "movie_test.py", line 25, in <module>
    writer.grab_frame()
  File "~/anaconda2/envs/test_movie/lib/python2.7/contextlib.py", line 35, in __exit__
    self.gen.throw(type, value, traceback)
  File "~/anaconda2/envs/test_movie/lib/python2.7/site-packages/matplotlib/animation.py", line 241, in saving
    self.finish()
  File "~/anaconda2/envs/test_movie/lib/python2.7/site-packages/matplotlib/animation.py", line 367, in finish
    self.cleanup()
  File "~/anaconda2/envs/test_movie/lib/python2.7/site-packages/matplotlib/animation.py", line 405, in cleanup
    out, err = self._proc.communicate()
  File "~/anaconda2/envs/test_movie/lib/python2.7/site-packages/subprocess32.py", line 927, in communicate
    stdout, stderr = self._communicate(input, endtime, timeout)
  File "~/anaconda2/envs/test_movie/lib/python2.7/site-packages/subprocess32.py", line 1713, in _communicate
    orig_timeout)
  File "~/anaconda2/envs/test_movie/lib/python2.7/site-packages/subprocess32.py", line 1769, in _communicate_with_poll
    register_and_append(self.stdout, select_POLLIN_POLLPRI)
  File "~/anaconda2/envs/test_movie/lib/python2.7/site-packages/subprocess32.py", line 1748, in register_and_append
    poller.register(file_obj.fileno(), eventmask)
ValueError: I/O operation on closed file

我所做的所有搜索都对应于相对简单的文本写入/输出操作，但不适用于视频。在此先感谢您的帮助!

Answer 1

事实证明这个错误非常小——我必须导入集群的 matplotlib。我不知道为什么会这样，因为 matplotlib 已经合并到 Python 包中。