If you wish to install Comix in another base directory, use the --installdir option. Example: python install.py install --installdir /usr. If you have installed with --installdir, do not forget to use the same option when uninstalling.
There is another option, --no-mime, that can be used to tell install.py that it should not register new mime types for cbz, cbr and cbt archives, or install the thumbnail creation script for these files that is used by some file managers (such as Nautilus and Thunar).
As an example of how to install Comix from the downloaded tar.gz file, run as the root user (via su or sudo):
# tar -xzf comix-x.y.z.tar.gz
# cd comix-x.y.z
# python install.py install
If you don't want to install Comix in some system directory, you can just execute the file src/comix.py in the unpacked Comix directory to run the program. You could also create a symlink somewhere in your PATH pointing to this file.
To use the library you need pysqlite (which is usually included in the standard library for Python 2.5 and later).
You also need either the unrar or the rar program from RARLAB installed if you wish to read
RAR (.cbr) archives.
Note that these packages do not necessarily contain the latest version of Comix. If you want to be sure about getting the latest version, you should install from the tarball above. Feel free to compile new Comix packages for your favourite package manager.