The expected convention for locally installed packages is to put them in the :file:`{...}/site-packages/` directory, but you may want to install Python modules into some arbitrary directory.For example, your site may have a convention of keeping all software related to the web server under :file:`/www`. Add-on Python modules might then belong in :file:`/www/python`, and in order to import them, this directory must be added to ``sys.path``.There are several different ways to add the directory.