我使用pip安装了matplotlib。 但是当我在ipython笔记本中尝试时，我无法导入它。 我写道，
import matplotlib.pyplot as plt
和输出
--------------------------------------------------------------------------
ValueError Traceback (most recent call last)
<ipython-input-67-eff513f636fd> in <module>()
----> 1 import matplotlib.pyplot as plt
/Users/yuchi/.pyenv/versions/3.5.0rc1/lib/python3.5/site-packages/matplotlib/__init__.py in <module>()
1129
1130 # this is the instance used by the matplotlib classes
-> 1131 rcParams = rc_params()
1132
1133 if rcParams['examples.directory']:
/Users/yuchi/.pyenv/versions/3.5.0rc1/lib/python3.5/site- packages/matplotlib/__init__.py in rc_params(fail_on_error)
973 return ret
974
--> 975 return rc_params_from_file(fname, fail_on_error)
976
977
/Users/yuchi/.pyenv/versions/3.5.0rc1/lib/python3.5/site-packages/matplotlib/__init__.py in rc_params_from_file(fname, fail_on_error, use_default_template)
1098 parameters specified in the file. (Useful for updating dicts.)
1099 """
-> 1100 config_from_file = _rc_params_in_file(fname, fail_on_error)
1101
1102 if not use_default_template:
/Users/yuchi/.pyenv/versions/3.5.0rc1/lib/python3.5/site-packages/matplotlib/__init__.py in _rc_params_in_file(fname, fail_on_error)
1016 cnt = 0
1017 rc_temp = {}
-> 1018 with _open_file_or_url(fname) as fd:
1019 try:
1020 for line in fd:
/Users/yuchi/.pyenv/versions/3.5.0rc1/lib/python3.5/contextlib.py in __enter__(self)
57 def __enter__(self):
58 try:
---> 59 return next(self.gen)
60 except StopIteration:
61 raise RuntimeError("generator didn't yield") from None
/Users/yuchi/.pyenv/versions/3.5.0rc1/lib/python3.5/site-packages/matplotlib/__init__.py in _open_file_or_url(fname)
998 else:
999 fname = os.path.expanduser(fname)
-> 1000 encoding = locale.getdefaultlocale()[1]
1001 if encoding is None:
1002 encoding = "utf-8"
/Users/yuchi/.pyenv/versions/3.5.0rc1/lib/python3.5/locale.py in getdefaultlocale(envvars)
557 else:
558 localename = 'C'
--> 559 return _parse_localename(localename)
560
561
/Users/yuchi/.pyenv/versions/3.5.0rc1/lib/python3.5/locale.py in _parse_localename(localename)
485 elif code == 'C':
486 return None, None
--> 487 raise ValueError('unknown locale: %s' % localename)
488
489 def _build_localename(localetuple):
ValueError: unknown locale: UTF-8
请告诉我解决方案。