code: def _get_schema_for_field(self, obj, field):
          
          mapping = self._get_default_mapping(obj)
          if hasattr(field, '_jsonschema_type_mapping'):
              schema = field._jsonschema_type_mapping()
          elif '_jsonschema_type_mapping' in field.metadata:
              schema = field.metadata['_jsonschema_type_mapping']
          elif field.__class__ in mapping:
              pytype = mapping[field.__class__]
              if isinstance(pytype, basestring):
                  schema = getattr(self, pytype)(obj, field)
              else:
                  schema = self._from_python_type(
                      obj, field, pytype
                  )
          else:
              raise ValueError('unsupported field type %s' % field)
  
          # Apply any and all validators that field may have
          for validator in field.validators:
              if validator.__class__ in FIELD_VALIDATORS:
                  schema = FIELD_VALIDATORS[validator.__class__](
                      schema, field, validator, obj
                  )
          return schema
docs: Get schema and validators for field.