Load the model fron environment variables

def load_env(self):
        """ Load the model fron environment variables
        """
        for key, value in self.spec.items():
            if value['type'] in (dict, list):
                envar = (self.env_prefix + "_" + key).upper()
                try:
                    envvar = env.json(envar,
                                      default=getattr(self, key.upper(), value.get('default')))
                except ConfigurationError as _err:  #pragma: no cover
                    print(_err)
                    self.log.critical(f"Error parsing json from env var. {os.environ.get(envar)}")
                    print(envar)
                    raise
            else:
                envvar = env((self.env_prefix + "_" + key).upper(),
                             default=getattr(self, key.upper(), value.get('default')),
                             cast=value['type'])
            setattr(self, key.upper(), envvar)