当我尝试使用pip升级我的matplotlib时,它输出:Downloading/unpackingmatplotlibfromhttps://pypi.python.org/packages/source/m/matplotlib/matplotlib-1.4.0.tar.gz#md5=1daf7f2123d94745feac1a30b210940cDownloadingmatplotlib-1.4.0.tar.gz(51.2MB):51.2MBdownloadedRunningsetup.py(path:/tmp/pip_build_root/matplotlib/setup.py