code: def _from_python_type(self, obj, field, pytype):
          
          json_schema = {
              'title': field.attribute or field.name,
          }
  
          for key, val in TYPE_MAP[pytype].items():
              json_schema[key] = val
  
          if field.dump_only:
              json_schema['readonly'] = True
  
          if field.default is not missing:
              json_schema['default'] = field.default
  
          # NOTE: doubled up to maintain backwards compatibility
          metadata = field.metadata.get('metadata', {})
          metadata.update(field.metadata)
  
          for md_key, md_val in metadata.items():
              if md_key == 'metadata':
                  continue
              json_schema[md_key] = md_val
  
          if isinstance(field, fields.List):
              json_schema['items'] = self._get_schema_for_field(
                  obj, field.container
              )
          return json_schema
docs: Get schema definition from python type.