我相信我用2.7：
正确安装了matplotlib$ pip install matplotlib
Requirement already satisfied (use --upgrade to upgrade): matplotlib in /usr/local/lib/python2.7/site-packages
Requirement already satisfied (use --upgrade to upgrade): numpy>=1.5 in /usr/local/lib/python2.7/site-packages (from matplotlib)
Requirement already satisfied (use --upgrade to upgrade): python-dateutil in /usr/local/lib/python2.7/site-packages (from matplotlib)
Requirement already satisfied (use --upgrade to upgrade): tornado in /usr/local/lib/python2.7/site-packages (from matplotlib)
Requirement already satisfied (use --upgrade to upgrade): pyparsing>=1.5.6,!=2.0.0 in /usr/local/lib/python2.7/site-packages (from matplotlib)
Requirement already satisfied (use --upgrade to upgrade): nose in /usr/local/lib/python2.7/site-packages (from matplotlib)
Requirement already satisfied (use --upgrade to upgrade): six in /usr/local/lib/python2.7/site-packages (from python-dateutil->matplotlib)
Requirement already satisfied (use --upgrade to upgrade): backports.ssl-match-hostname in /usr/local/lib/python2.7/site-packages (from tornado->matplotlib)
Cleaning up...
但是当我用它运行一个例子时出现以下错误：
python rl.py
Traceback (most recent call last):
File "rl.py", line 21, in <module>
import pylab
File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/pylab.py", line 1, in <module>
from matplotlib.pylab import *
File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/matplotlib/pylab.py", line 221, in <module>
from matplotlib import mpl # pulls in most modules
File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/matplotlib/mpl.py", line 3, in <module>
from matplotlib import axes
File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/matplotlib/axes.py", line 19, in <module>
import matplotlib.dates as mdates
File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/matplotlib/dates.py", line 119, in <module>
from dateutil.rrule import rrule, MO, TU, WE, TH, FR, SA, SU, YEARLY, \
ImportError: No module named dateutil.rrule