Incorrect default backend set for matplotlib after installing pyside

[skirpichev]

After installation, matplotlibrc has backend : pyside line, and when I try to import one from the IPython's qtconsole it emits a warning:

/home/sk/.virtualenvs/ipy/local/lib/python2.7/site-packages/matplotlib/__init__.py:1039: UserWarning: Bad val "pyside" on line #38
    "backend      : pyside
"
    in file "/home/sk/.virtualenvs/ipy/local/lib/python2.7/site-packages/matplotlib/mpl-data/matplotlibrc"
    Key backend: Unrecognized backend string "pyside": valid strings are [u'pgf', u'cairo', u'MacOSX', u'CocoaAgg', u'gdk', u'ps', u'GTKAgg', u'nbAgg', u'GTK', u'Qt5Agg', u'template', u'emf', u'GTK3Cairo', u'GTK3Agg', u'WX', u'Qt4Agg', u'TkAgg', u'agg', u'svg', u'GTKCairo', u'WXAgg', u'WebAgg', u'pdf']
  (val, error_details, msg))

Perhaps, something was left after #3387.

See also this thread on SO.

[WeatherGod]

Hmm, unlikely. I suspect that an older version of matplotlib is getting
picked up. What does "matplotlib.version" say?

On Fri, Aug 7, 2015 at 12:30 PM, Sergey B Kirpichev <
notifications@github.com> wrote:

After installation, matplotlibrc has backend : pyside line, and when I
try to import one from the IPython's qtconsole it emits a warning:

/home/sk/.virtualenvs/ipy/local/lib/python2.7/site-packages/matplotlib/init.py:1039: UserWarning: Bad val "pyside" on line #38
"backend : pyside
"
in file "/home/sk/.virtualenvs/ipy/local/lib/python2.7/site-packages/matplotlib/mpl-data/matplotlibrc"
Key backend: Unrecognized backend string "pyside": valid strings are [u'pgf', u'cairo', u'MacOSX', u'CocoaAgg', u'gdk', u'ps', u'GTKAgg', u'nbAgg', u'GTK', u'Qt5Agg', u'template', u'emf', u'GTK3Cairo', u'GTK3Agg', u'WX', u'Qt4Agg', u'TkAgg', u'agg', u'svg', u'GTKCairo', u'WXAgg', u'WebAgg', u'pdf'](val, error_details, msg))

Perhaps, something was left after #3387
#3387.

See also this thread
http://stackoverflow.com/questions/28168542/incorrect-default-backend-set-for-matplotlib-after-installing-pyside
on SO.

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#4883.

[skirpichev]

On Fri, Aug 07, 2015 at 10:06:41AM -0700, Benjamin Root wrote:

Hmm, unlikely. I suspect that an older version of matplotlib is getting
picked up. What does "matplotlib.version" say?

The latest release:
~ $ workon ipy
(ipy):~ $ python
Python 2.7.3 (default, Mar 13 2014, 11:03:55)
[GCC 4.7.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.

import matplotlib; matplotlib.version
'1.4.3'
^D
(ipy):~ $

[tacaswell]

Can you paste in the header of the build output? I am interested in exactly which existing modules mpl found and how you set up your venv.

[skirpichev]

On Fri, Aug 07, 2015 at 01:43:02PM -0700, Thomas A Caswell wrote:

Can you paste in the header of the build output? I am interested in
exactly which existing modules mpl found

egg_info? Attached at the end.

and how you set up your venv.

Minimal reproducible example on the Debian Wheezy:
$ mkvirtualenv test
$ pip install pyside
$ pip install matplotlib
$ python
Python 2.7.3 (default, Mar 13 2014, 11:03:55)
[GCC 4.7.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.

import matplotlib
/home/sk/.virtualenvs/test/local/lib/python2.7/site-packages/matplotlib/init.py:1039: UserWarning: Bad val "pyside" on line #38
"backend : pyside
"
in file "/home/sk/.virtualenvs/test/local/lib/python2.7/site-packages/matplotlib/mpl-data/matplotlibrc"
Key backend: Unrecognized backend string "pyside": valid strings are [u'pgf', u'cairo', u'MacOSX', u'CocoaAgg', u'gdk', u'ps', u'GTKAgg', u'nbAgg', u'GTK', u'Qt5Agg', u'template', u'emf', u'GTK3Cairo', u'GTK3Agg', u'WX', u'Qt4Agg', u'TkAgg', u'agg', u'svg', u'GTKCairo', u'WXAgg', u'WebAgg', u'pdf'](val, error_details, msg))

Running setup.py egg_info for package matplotlib
============================================================================
Edit setup.cfg to change the build options

BUILDING MATPLOTLIB
            matplotlib: yes [1.4.3]
                python: yes [2.7.3 (default, Mar 13 2014, 11:03:55)  [GCC
                        4.7.2]]
              platform: yes [linux2]

REQUIRED DEPENDENCIES AND EXTENSIONS
                 numpy: yes [not found. pip may install it below.]
                   six: yes [six was not found.pip will attempt to install
                        it after matplotlib.]
              dateutil: yes [dateutil was not found. It is required for date
                        axis support. pip/easy_install may attempt to
                        install it after matplotlib.]
                  pytz: yes [pytz was not found. pip will attempt to install
                        it after matplotlib.]
               tornado: yes [tornado was not found. It is required for the
                        WebAgg backend. pip/easy_install may attempt to
                        install it after matplotlib.]
             pyparsing: yes [pyparsing was not found. It is required for
                        mathtext support. pip/easy_install may attempt to
                        install it after matplotlib.]
                 pycxx: yes [Couldn't import.  Using local copy.]
                libagg: yes [pkg-config information for 'libagg' could not
                        be found. Using local copy.]
              freetype: yes [version 2.4.9]
                   png: yes [version 1.2.49]
                 qhull: yes [pkg-config information for 'qhull' could not be
                        found. Using local copy.]

OPTIONAL SUBPACKAGES
           sample_data: yes [installing]
              toolkits: yes [installing]
                 tests: yes [nose 0.11.1 or later is required to run the
                        matplotlib test suite.  pip/easy_install may attempt
                        to install it after matplotlib. / mock is required
                        to run the matplotlib test suite.  pip/easy_install
                        may attempt to install it after matplotlib.]
        toolkits_tests: yes [nose 0.11.1 or later is required to run the
                        matplotlib test suite.  pip/easy_install may attempt
                        to install it after matplotlib. / mock is required
                        to run the matplotlib test suite.  pip/easy_install
                        may attempt to install it after matplotlib.]

OPTIONAL BACKEND EXTENSIONS
                macosx: no  [Mac OS-X only]
                qt5agg: no  [PyQt5 not found]
                qt4agg: no  [PyQt4 not found]
                pyside: yes [installing, Qt: 4.8.6, PySide: 1.2.2]
               gtk3agg: no  [Requires pygobject to be installed.]
Running from numpy source directory.

[tacaswell]

Thanks! That information is perfect.

[tacaswell]

What is behind mkvirtualenv test? I went with pyvenv create test; source test/bin/activate

[skirpichev]

On Sun, Aug 09, 2015 at 09:48:26PM -0700, Thomas A Caswell wrote:

What is behind mkvirtualenv test?

https://virtualenvwrapper.readthedocs.org/

I went with pyvenv create test; source
test/bin/activate

virtualenvwrapper uses virtualenv, but I don't think that matter.

[tacaswell]

I can confirm this happens, no idea why.

[tacaswell]

Closing as this is fixed on master and will be fixed for 1.5 #3387 actually fixed this problem with https://github.com/matplotlib/matplotlib/pull/3387/files#diff-c28358ce9623af21f7b6e068f69085b7L2022 which removes the name 'pyside' which is used here: https://github.com/matplotlib/matplotlib/blob/master/setup.py#L280 to set the value of the default backend which is written out into the base rc file here: https://github.com/matplotlib/matplotlib/blob/master/setup.py#L319