set_post_format( int|WP_Post $post, string $format ): array|WP_Error|false

70function set_post_format( $post, $format ) {71	$post = get_post( $post );72 73	if ( ! $post ) {74		return new WP_Error( 'invalid_post', __( 'Invalid post.' ) );75	}76 77	if ( ! empty( $format ) ) {78		$format = sanitize_key( $format );79		if ( 'standard' === $format || ! in_array( $format, get_post_format_slugs(), true ) ) {80			$format = '';81		} else {82			$format = 'post-format-' . $format;83		}84	}85 86	return wp_set_post_terms( $post->ID, $format, 'post_format' );87}