Travis error: _tkinter.TclError: no display name and no $DISPLAY environment variable

[sylhare]

Travis pops up this error when trying to run p.sacksplot():
_tkinter.TclError: no display name and no $DISPLAY environment variable

It seems it is related to the line using matplotlib:
plt.figure()

[sylhare]

You can find the answer at stackoverflow/tkinter-tclerror-no-display-name-and-no-display-environment-variable

I used this answer to set the backend of matloblib before pyplot is loaded from here

import os
import matplotlib as mpl
if os.environ.get('DISPLAY','') == '':
   print('no display found. Using non-interactive Agg backend')
   mpl.use('Agg')
import matplotlib.pyplot as plt

For some more information on this issue:

• Matplotlib documentation
• Another stackoverflow answser
• A github issue with the same kind of answser (I was using spyder)