[Debian] Install Python 3.4 on Debian 7 (Wheezy)

Install dependencies

$ [sudo] apt-get install \
build-essential \
libncurses5-dev \
libncursesw5-dev \
libreadline6-dev \
libdb5.1-dev \
libgdbm-dev \
libsqlite3-dev \
libssl-dev \
libbz2-dev \
libexpat1-dev \
liblzma-dev \
zlib1g-dev

Download python 3 from python.org website and uncompress it

$ cd /tmp \
&& wget https://www.python.org/ftp/python/3.4.3/Python-3.4.3.tgz \
&& tar -zxf Python-3.4.3.tgz \
&& cd /tmp/Python-3.4.3 \
&& [sudo] ./configure --prefix=/opt/python-3.4.3 \
&& [sudo] make \
&& [sudo] make install

Add new python3 installation location to PATH

$ export PATH="/opt/python-3.4.3/bin/:$PATH"
$ echo '!!' >> ~/.bashrc