Debian7自带的是python2.7。
安装Python3编译所依赖的包
sudo apt-get install build-essential -y
sudo apt-get install libncurses5-dev libncursesw5-dev libreadline6-dev -y
sudo apt-get install libdb5.3-dev libgdbm-dev libsqlite3-dev libssl-dev -y
sudo apt-get install libbz2-dev libexpat1-dev liblzma-dev zlib1g-dev -y
sudo apt-get install libssl-dev openssl -y
下载python3.5
wget --no-check-certificate https://www.python.org/ftp/python/3.5.1/Python-3.5.1.tgz
安装编译
tar xzvf Python-3.5.1.tgz
cd Python-3.5.1
./configure --prefix=/usr/local/python35
make all
sudo make install