$ json_schema_generator.py record http://somewhere.com/any.json file.json_schema
It creates file.json_schema file containing the generated json schema
$ json_schema_generator.py validate http://somewhere.com/any.json file.json_schema
It validates if the json validates with file.json_schema
$ json_schema_generator.py homologate http://somewhere.com/immutable.json immutable
It should create (or replace) a fixture file called json_schemas/immutable.json_schema and a test file called test_immutable_jsonschema.py in the current dir.
If you want to create it in another path use --path /wanted/path/dir/