PyTyle is currently not available from the Arch repos. The original PyTyle and PyTyle2 are available on the AUR here and here respectively. Both can be installed on the same system, although only one can be run at the same time.
After installation, PyTyle can be run simply by entering this into the terminal:
Alternatively, if you want to run PyTyle2, you would run
After you have started PyTyle for the first time, a new configuration directory should appear in your XDG_CONFIG_HOME directory (usually ~/.config/) called pytyle2. Inside this directory is config.ini. All of the configuration options are stored there. I haven't really documented the options yet, so your guess will have to do at the moment.