validation.py 文件源码

def validate_readonly_fields(self, cls, model):
        " Validate that readonly_fields refers to proper attribute or field. "
        if hasattr(cls, "readonly_fields"):
            check_isseq(cls, "readonly_fields", cls.readonly_fields)
            for idx, field in enumerate(cls.readonly_fields):
                if not callable(field):
                    if not hasattr(cls, field):
                        if not hasattr(model, field):
                            try:
                                model._meta.get_field(field)
                            except FieldDoesNotExist:
                                raise ImproperlyConfigured(
                                    "%s.readonly_fields[%d], %r is not a callable or "
                                    "an attribute of %r or found in the model %r."
                                    % (cls.__name__, idx, field, cls.__name__, model._meta.object_name)
                                )