Graphs are not displayed using matplotlib plt.show ()

Question

I'm really new to Python and Linux and I need help, I tried using matplotlib to show a simple plot like this:

from matplotlib import pyplot as plt plt.plot([5,6,7,8], [7,3,8,3]) plt.show() 

But, when I run python3 test.py , I get the following output:

 /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) 

and an empty figure without a white canvas:

What's wrong? How can i fix this?

Answer 1

As you can see:

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

So, the submitted proposal :

 Try installing cairocffi. 

The installation guide for cairocffi pretty straight forward. If dependencies ¹ are fulfilled, it is as simple as:

 pip install cairocffi 

---

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

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