matplotlib.use('nbagg ') does not work in Python 3

[stahlous]

This snippet:

import matplotlib
matplotlib.use('nbagg')
from matplotlib import pyplot as plt

Results in this traceback:

---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-5-68fd53519d64> in <module>()
      1 import matplotlib
      2 matplotlib.use('nbagg')
----> 3 from matplotlib import pyplot as plt

C:\Miniconda\envs\py34\lib\site-packages\matplotlib\pyplot.py in <module>()
    106 
    107 from matplotlib.backends import pylab_setup
--> 108 _backend_mod, new_figure_manager, draw_if_interactive, _show = pylab_setup()
    109 
    110 

C:\Miniconda\envs\py34\lib\site-packages\matplotlib\backends\__init__.py in pylab_setup()
     30     # imports. 0 means only perform absolute imports.
     31     backend_mod = __import__(backend_name,
---> 32                              globals(),locals(),[backend_name],0)
     33 
     34     # Things we pull in from all backends

C:\Miniconda\envs\py34\lib\site-packages\matplotlib\backends\backend_nbagg.py in <module>()
     10 
     11 from matplotlib.figure import Figure
---> 12 from matplotlib.backends.backend_webagg_core import (FigureManagerWebAgg,
     13                                                      FigureCanvasWebAggCore,
     14                                                      NavigationToolbar2WebAgg)

C:\Miniconda\envs\py34\lib\site-packages\matplotlib\backends\backend_webagg_core.py in <module>()
    239 
    240 
--> 241 class NavigationToolbar2WebAgg(backend_bases.NavigationToolbar2):
    242     _jquery_icon_classes = {
    243         'home': 'ui-icon ui-icon-home',

C:\Miniconda\envs\py34\lib\site-packages\matplotlib\backends\backend_webagg_core.py in NavigationToolbar2WebAgg()
    255                  for text, tooltip_text, image_file, name_of_method
    256                  in (backend_bases.NavigationToolbar2.toolitems +
--> 257                      (('Download', 'Download plot', 'download', 'download'),))
    258                  if image_file in _jquery_icon_classes]
    259 

C:\Miniconda\envs\py34\lib\site-packages\matplotlib\backends\backend_webagg_core.py in <listcomp>(.0)
    256                  in (backend_bases.NavigationToolbar2.toolitems +
    257                      (('Download', 'Download plot', 'download', 'download'),))
--> 258                  if image_file in _jquery_icon_classes]
    259 
    260     def _init_toolbar(self):

NameError: name '_jquery_icon_classes' is not defined

And this, I believe, is why:

http://stackoverflow.com/questions/13905741/accessing-class-variables-from-a-list-comprehension-in-the-class-definition

Thanks!

[tacaswell]

cc @pelson @mdboom

[astrojuanlu]

Confirmed on both 3.3 and 3.4, everything works as expected on Python 2.7.

I tried to solve the issue in a hacky way just replacing the variable names with their contents, but still everything I see is a blank plot.

[jenshnielsen]

Yes, @stahlous is right. The simplest is probably to rewrite the list comprehensions as regular for loops.