VirtualEnv環境でmatplotlibなどがimportできない

環境

• Python 3.4.3(Pyenvにて)
• ipython==4.0.1
• matplotlib==1.5.0
• notebook==4.0.6

2015年12月11日現在最新版がはいってるということ

エラー内容

Traceback (most recent call last):
File "", line 1, in
File "/Users/user/graph/lib/python3.4/site-packages/matplotlib/init.py", line 1131, in
rcParams = rc_params()
File "/Users/user/graph/lib/python3.4/site-packages/matplotlib/init.py", line 975, in rc_params
return rc_params_from_file(fname, fail_on_error)
File "/Users/user/graph/lib/python3.4/site-packages/matplotlib/init.py", line 1100, in rc_params_from_file
config_from_file = _rc_params_in_file(fname, fail_on_error)
File "/Users/user/graph/lib/python3.4/site-packages/matplotlib/init.py", line 1018, in _rc_params_in_file
with _open_file_or_url(fname) as fd:
File "/Users/user/.pyenv/versions/3.4.3/lib/python3.4/contextlib.py", line 59, in enter
return next(self.gen)
File "/Users/user/graph/lib/python3.4/site-packages/matplotlib/init.py", line 1000, in _open_file_or_url
encoding = locale.getdefaultlocale()[1]
File "/Users/user/graph/lib/python3.4/locale.py", line 556, in getdefaultlocale
return _parse_localename(localename)
File "/Users/user/graph/lib/python3.4/locale.py", line 484, in _parse_localename
raise ValueError('unknown locale: %s' % localename)
ValueError: unknown locale: UTF-8

要はlocale: UTF-8

locale設定

export

(graph)pc-name:graph user$ export LC_ALL='ja_JP.UTF-8'

確認

(graph)pc-name:graph user$ locale
LANG=
LC_COLLATE="ja_JP.UTF-8"
LC_CTYPE="ja_JP.UTF-8"
LC_MESSAGES="ja_JP.UTF-8"
LC_MONETARY="ja_JP.UTF-8"
LC_NUMERIC="ja_JP.UTF-8"
LC_TIME="ja_JP.UTF-8"
LC_ALL="ja_JP.UTF-8"     # こいつ

再度importできるか

>>> import matplotlib.pyplot
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/user/.pyenv/versions/3.4.3/lib/python3.4/site-packages/matplotlib/pyplot.py", line 114, in <module>
    _backend_mod, new_figure_manager, draw_if_interactive, _show = pylab_setup()
  File "/Users/user/.pyenv/versions/3.4.3/lib/python3.4/site-packages/matplotlib/backends/__init__.py", line 32, in pylab_setup
    globals(),locals(),[backend_name],0)
  File "/Users/user/.pyenv/versions/3.4.3/lib/python3.4/site-packages/matplotlib/backends/backend_macosx.py", line 24, in <module>
    from matplotlib.backends import _macosx
RuntimeError: Python is not installed as a framework. The Mac OS X backend will not be able to function correctly if Python is not installed as a framework. See the Python documentation for more information on installing Python as a framework on Mac OS X. Please either reinstall Python as a framework, or try one of the other backends. If you are Working with Matplotlib in a virtual enviroment see 'Working with Matplotlib in Virtual environments' in the Matplotlib FAQ

まだなんかでる...

~/.matplotlib/matplotlibrcを作成

backend : TkAgg

を追加

別解

また、 @aion さんからご指摘をいただき以下でもこのエラーへの対策ができるそうです！
@aion さんありがとうございます

import matplotlib
matplotlib.use('TkAgg')