pyOBD is an OBD-II compliant car diagnostic tool. It is designed to interface with low-cost ELM 32x OBD-II diagnostic interfaces such as ELM-USB. It will basically allow you to talk to your car's ECU, display fault codes, display measured values, read status tests, etc. All cars made since 1996 (in the US) or 2001 (in the EU) must be OBD-II compliant, i.e. they should work with pyOBD.