Python 3.x版本使用pip3，它会把你想下载的包放到usr/local/lib/python3.5/dist-packages/下，而非usr/local/lib/python2.7/dist-packages/下
sudo apt-get install python3-pip
sudo pip3 install --upgrade pip
sudo pip3 install numpy
sudo pip3 install scipy
sudo pip3 install matplotlib
原文：http://www.cnblogs.com/McKean/p/6414651.html