Making python 3.3 default python 3 interpreter instead of 3.2

You can custom your python3 alias. For this, you can modify your .bashrc file by appending "alias python3='python3.3'" at the end of it. This shell script can do it for you :

#!/bin/bash

cd ~

# Create the ~/.bashrc file if it does not exist
if [ ! -f ./.bashrc ]; then
    touch .bashrc
    chmod 755 .bashrc
    echo "#!/bin/bash" >> .bashrc
fi

# Append the customed alias
echo " " >> .bashrc
echo "alias python3='python3.3'" >> .bashrc
echo " " >> .bashrc

# Reload settings in the .bashrc script
source .bashrc

You may run different python versions on the same system by setting up the appropriate environment variables. This would allow you to locally install a later version of Python than the synaptic package manager might offer. e.g. in a file (mysetup) have:

TK_LIBRARY=/usr/lib/python2.7/lib-tk:/usr/lib/python2.7/site-packages/PIL:/usr/lib   
TKPATH=/usr/lib/python2.7/lib-tk:/usr/lib/python2.7/site-packages/PIL:/usr/lib 
TCL_LIBRARY=/usr/lib 
export TCL_LIBRARY TK_LIBRARY TKKPATH   

export PYTHONPATH=/usr/lib/python2.7/lib-tk:/usr/lib/python2.7/lib-stdwin:/usr/lib/python2.7/lib-dynload:/usr/lib:.     

and put them into your environment with . mysetup