PySTDF is a Python module which makes it easy to work with STDF (Teradyne's Standard Test Data Format). STDF is a commonly-used file format in semiconductor tests. Automated test equipment (ATE) from such vendors as Teradyne, Verigy, LTX, Credence, and others supports this format. PySTDF provides event-based stream parsing of STDF version 4, indexers that help structure the data into a more useful tabular form, and the ability to generate missing summary records or new types of derivative records. The parser architecture is very flexible and can easily be extended to support STDF version 3 and custom record types.