The pyjson-tricks package brings several pieces of functionality to python handling of json files: (1) store and load numpy arrays in human-readable format; (2) store and load class instances both generic and customized; (3) store and load date/times as a dictionary (including timezone); (4) preserve map order {} using OrderedDict; (5) allow for comments in json files by starting lines with #; (6) sets, complex numbers, decimal, fraction, enums, compression, duplicate keys, etc. As well as compression and disallowing duplicate keys.