我正在尝试使用 ggplot for Python 在 iPython Notebook 中工作，但是在运行时from ggplot import *出现以下错误：
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
<ipython-input-22-2199c088d178> in <module>()
2 import numpy as np
3 import dateutil
----> 4 from ggplot import *
~/ipython-venv/lib/python2.7/site-packages/ggplot/__init__.py in <module>()
19 __version__ = '0.6.8'
20
---> 21 from .qplot import qplot
22 from .ggplot import ggplot
23 from .components import aes
~/ipython-venv/lib/python2.7/site-packages/ggplot/qplot.py in <module>()
3
4 import ggplot
----> 5 from .components import aes
6 from .geoms import geom_point, geom_bar, geom_boxplot, geom_histogram, geom_line
7 from .geoms.chart_components import xlab as xlabel
~/ipython-venv/lib/python2.7/site-packages/ggplot/components/__init__.py in <module>()
2 unicode_literals)
3 from .aes import aes
----> 4 from . import colors, shapes, size, linetypes, alphas
5
6
~/ipython-venv/lib/python2.7/site-packages/ggplot/components/colors.py in <module>()
4 import numpy as np
5 from matplotlib.colors import rgb2hex
----> 6 from ..utils.color import ColorHCL
7 from .legend import get_labels
8 from copy import deepcopy
~/ipython-venv/lib/python2.7/site-packages/ggplot/utils/__init__.py in <module>()
2 unicode_literals)
3
----> 4 from .ggutils import ggsave, add_ggplotrc_params
5 from .date_breaks import date_breaks
6 from .date_format import date_format
~/ipython-venv/lib/python2.7/site-packages/ggplot/utils/ggutils.py in <module>()
4 unicode_literals)
5
----> 6 import matplotlib.pyplot as plt
7 import json
8 import os
~/ipython-venv/lib/python2.7/site-packages/matplotlib/pyplot.py in <module>()
27 from cycler import cycler
28 import matplotlib
---> 29 import matplotlib.colorbar
30 from matplotlib import style
31 from matplotlib import _pylab_helpers, interactive
~/ipython-venv/lib/python2.7/site-packages/matplotlib/colorbar.py in <module>()
32 import matplotlib.artist as martist
33 import matplotlib.cbook as cbook
---> 34 import matplotlib.collections as collections
35 import matplotlib.colors as colors
36 import matplotlib.contour as contour
~/ipython-venv/lib/python2.7/site-packages/matplotlib/collections.py in <module>()
25 import matplotlib.artist as artist
26 from matplotlib.artist import allow_rasterization
---> 27 import matplotlib.backend_bases as backend_bases
28 import matplotlib.path as mpath
29 from matplotlib import _path
~/ipython-venv/lib/python2.7/site-packages/matplotlib/backend_bases.py in <module>()
60
61 import matplotlib.tight_bbox as tight_bbox
---> 62 import matplotlib.textpath as textpath
63 from matplotlib.path import Path
64 from matplotlib.cbook import mplDeprecation, warn_deprecated
~/ipython-venv/lib/python2.7/site-packages/matplotlib/textpath.py in <module>()
13 from matplotlib.path import Path
14 from matplotlib import rcParams
---> 15 import matplotlib.font_manager as font_manager
16 from matplotlib.ft2font import FT2Font, KERNING_DEFAULT, LOAD_NO_HINTING
17 from matplotlib.ft2font import LOAD_TARGET_LIGHT
~/ipython-venv/lib/python2.7/site-packages/matplotlib/font_manager.py in <module>()
1419 verbose.report("Using fontManager instance from %s" % _fmcache)
1420 except:
-> 1421 _rebuild()
1422 else:
1423 _rebuild()
~/ipython-venv/lib/python2.7/site-packages/matplotlib/font_manager.py in _rebuild()
1404 def _rebuild():
1405 global fontManager
-> 1406 fontManager = FontManager()
1407 if _fmcache:
1408 pickle_dump(fontManager, _fmcache)
~/ipython-venv/lib/python2.7/site-packages/matplotlib/font_manager.py in __init__(self, size, weight)
1042 # Load TrueType fonts and create font dictionary.
1043
-> 1044 self.ttffiles = findSystemFonts(paths) + findSystemFonts()
1045 self.defaultFamily = {
1046 'ttf': 'Bitstream Vera Sans',
~/ipython-venv/lib/python2.7/site-packages/matplotlib/font_manager.py in findSystemFonts(fontpaths, fontext)
322 fontfiles[f] = 1
323
--> 324 for f in get_fontconfig_fonts(fontext):
325 fontfiles[f] = 1
326
~/ipython-venv/lib/python2.7/site-packages/matplotlib/font_manager.py in get_fontconfig_fonts(fontext)
274 pipe = subprocess.Popen(['fc-list', '--format=%{file}\\n'],
275 stdout=subprocess.PIPE,
--> 276 stderr=subprocess.PIPE)
277 output = pipe.communicate()[0]
278 except (OSError, IOError):
/usr/local/Cellar/python/2.7.11/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.pyc in __init__(self, args, bufsize, executable, stdin, stdout, stderr, preexec_fn, close_fds, shell, cwd, env, universal_newlines, startupinfo, creationflags)
708 p2cread, p2cwrite,
709 c2pread, c2pwrite,
--> 710 errread, errwrite)
711 except Exception:
712 # Preserve original exception in case os.close raises.
/usr/local/Cellar/python/2.7.11/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.pyc in _execute_child(self, args, executable, preexec_fn, close_fds, cwd, env, universal_newlines, startupinfo, creationflags, shell, to_close, p2cread, p2cwrite, c2pread, c2pwrite, errread, errwrite)
1332 if e.errno != errno.ECHILD:
1333 raise
-> 1334 child_exception = pickle.loads(data)
1335 raise child_exception
1336
/usr/local/Cellar/python/2.7.11/Frameworks/Python.framework/Versions/2.7/lib/python2.7/pickle.pyc in loads(str)
1386 def loads(str):
1387 file = StringIO(str)
-> 1388 return Unpickler(file).load()
1389
1390 # Doctest
/usr/local/Cellar/python/2.7.11/Frameworks/Python.framework/Versions/2.7/lib/python2.7/pickle.pyc in load(self)
862 while 1:
863 key = read(1)
--> 864 dispatch[key](self)
865 except _Stop, stopinst:
866 return stopinst.value
/usr/local/Cellar/python/2.7.11/Frameworks/Python.framework/Versions/2.7/lib/python2.7/pickle.pyc in load_string(self)
970 if rep.startswith(q):
971 if len(rep) < 2 or not rep.endswith(q):
--> 972 raise ValueError, "insecure string pickle"
973 rep = rep[len(q):-len(q)]
974 break
ValueError: insecure string pickle
运行环境在OS-X El Capitan上，通过HomeBrew安装Python 2.x，安装了以下库：
(ipython-venv)➜ ~ pip list appnope (0.1.0) backports-abc (0.4) backports.ssl-match-hostname (3.5.0.1) beautifulsoup4 (4.4.1) brewer2mpl (1.4.1) certifi (2015.11.20.1) ) 循环器 (0.9.0) 装饰器 (4.0.6) functools32 (3.2.3.post2) ggplot (0.6.8) gnureadline (6.3.3) ipykernel (4.2.2) ipython (4.0.3) ipython-genutils (0.1 .0) Jinja2 (2.8) jsonschema (2.5.1) jupyter-client (4.1.1) jupyter-core (4.0.6) MarkupSafe (0.23) matplotlib (1.5.1) mechanize (0.2.5) misune (0.7.1) ) nbconvert (4.1.0) nbformat (4.0.1) notebook (4.1.0) numpy (1.10.4) pandas (0.17.1) path.py (8.1.2) patsy (0.4.1) pexpect (4.0.1 ) pickleshare (0.6) pip (8.0.2) ptyprocess (0.5) Pygments (2.1) pyparsing (2.1.0) python-dateutil (2.4.2) pytz (2015.7) pyzmq (15.2.0) scipy (0.17.0) selenium (2.50.0) setuptools (15.0) simplegeneric (0.8.1) singledispatch (3.4.0.3) 六 (1.10.0) statsmodels (0.6.1) termcolor (1.1.0) terminado (0.6) tornado (4.3) traitlets (4.1.0)