python@gentoo.org Python facelessuser/backrefs backrefs Backrefs is a wrapper around Python's built-in Re and the 3rd party Regex library. Backrefs adds various additional back references (and a couple other features) that are known to some regular expression engines, but not to Python's Re and/or Regex. The supported back references actually vary depending on the regular expression engine being used as the engine may already have support for some.