The Python installation is done in the "Framework" folder.
There are two locations for the "Python.framework":
/System/Library/Frameworks
/Library/Frameworks
Your own Python installation upgrades will go to the second location.
There are 4 items Inside "Python.framework":
Headers -> Versions/Current/Headers -> Versions/2.7/include/
Python -> Versions/Current/Python
Resources -> Versions/Current/Resources/
Versions/
2.7/
Current -> 2.7/
In ".bash_profile", you can set the 'PYTHONHOME' and 'PATH'
export PYTHONHOME="/Library/Frameworks/Python.framework/Versions/Current"
or
export PYTHONHOME="/Library/Frameworks/Python.framework/Versions/2.7"
and
PATH="${PYTHONHOME}/bin:${PATH}"
export PATH
The ln command can be used to update the soft link "Current" in the Versions directory.
%> sudo ln -s 2.7 Current
Also check location '/usr/local/bin/' for more python soft link/aliases.