使用 matplotlib plt.show() 绘图不可见

我对 Python 和 Linux 非常陌生，我需要帮助，我尝试使用 matplotlib 按以下方式显示简单的绘图：

from matplotlib import pyplot as plt

plt.plot([5,6,7,8], [7,3,8,3])
plt.show()

但是，当我跑步时python3 test.py，我得到以下输出：

/usr/local/lib/python3.4/dist-packages/matplotlib/backends/backend_gtk3agg.py:18: UserWarning: The Gtk3Agg backend is known to not work on Python 3.x with pycairo. Try installing cairocffi.
  "The Gtk3Agg backend is known to not work on Python 3.x with pycairo. "
Traceback (most recent call last):
  File "/usr/local/lib/python3.4/dist-packages/matplotlib/backends/backend_gtk3agg.py", line 69, in on_draw_event
    buf, cairo.FORMAT_ARGB32, width, height)
NotImplementedError: Surface.create_for_data: Not Implemented yet.
Traceback (most recent call last):
  File "/usr/local/lib/python3.4/dist-packages/matplotlib/backends/backend_gtk3agg.py", line 69, in on_draw_event
    buf, cairo.FORMAT_ARGB32, width, height)
NotImplementedError: Surface.create_for_data: Not Implemented yet.
/usr/local/lib/python3.4/dist-packages/matplotlib/backends/backend_gtk3.py:215: Warning: Source ID 7 was not found when attempting to remove it
  GLib.source_remove(self._idle_event_id)

和一个没有白色画布的空图形：

怎么了？我该如何修复它？

如你看到的：

"The Gtk3Agg backend is known to not work on Python 3.x with pycairo."

所以建议提出的是：

Try installing cairocffi.

The installation guide https://pythonhosted.org/cairocffi/overview.html for cairocffi is pretty straight-forward. If the dependencies¹ are met it is as simple as:

pip install cairocffi

^{1) The dependencies for Python 3.x should logically be:}

sudo apt-get install python3-dev
sudo apt-get install libffi-dev