ams.io# AMS input parsers and output formatters. Functions guess(system) Guess the input format based on extension and content. parse(system) Parse input file with the given format in system.files.input_format. Modules json Json reader and writer for AMS. matpower MATPOWER parser. psse PSS/E .raw reader for AMS. pypower PYPOWER reader for AMS. xlsx Excel reader and writer for AMS.