What version of Mac OS X are you using, what is your PATH, and did you install another version of Python using MacPython, or did you install it through MacPorts? On Mac OS X 10.6 Snow Leopard, the following command works fine when installing dateutils in the system version of Python.
sudo easy_install -O2 dateutils
Please note that if your second Python installation also has setuptools installed, and if this easy_install utility overrides the default value in PATH, it will be installed in another Python.
source
share