My python environment was installed by downloading the official python installer for Mac. Django was installed in:
/Library/Frameworks/Python.framework/Version/2.7/lib/Python2.7/site-packages/
I used the automatic configuration in Titanium Studio → Preferences → PyDev → Interpreter-python to setup the interpreter. It did a good job, but...
/Library/Frameworks/Python.framework/Version/2.7/lib/Python2.7/site-packages/
...was not included, so a Django project cannot be created.
I want to add the site-packages manually. Although the site-package can be found in Finder, it does not show in the Titanium browser. I don't know why?!