compat.py 文件源码

def prefix_validation_error(error, prefix, code, params):
        """
        Prefix a validation error message while maintaining the existing
        validation data structure.
        """
        if error.error_list == [error]:
            error_params = error.params or {}
            return ValidationError(
                # We can't simply concatenate messages since they might require
                # their associated parameters to be expressed correctly which
                # is not something `string_concat` does. For example, proxied
                # ungettext calls require a count parameter and are converted
                # to an empty string if they are missing it.
                message=string_concat(
                    SimpleLazyObject(lambda: prefix % params),
                    SimpleLazyObject(lambda: error.message % error_params),
                ),
                code=code,
                params=dict(error_params, **params),
            )
        return ValidationError([
            prefix_validation_error(e, prefix, code, params)
            for e in error.error_list
        ])