I'll refer you to the original source where I picked up this trick: http://chimera.labs.oreilly.com/books/1230000000393/ch01.html#generatorargs http://chimera.l

I'll refer you to the original source where I picked up this trick: http://chimera.labs.oreilly.com/books/1230000000393/ch01.html#generatorargs http://chimera.labs.oreilly.com/books/1230000000393/ch01.htm... "Transforming and Reducing Data at the Same Time" I highly recommend David Beazley's excellent book, it made me a much better Python developer, helping me produce both idiomatic and efficient solutions over the last year. That book is programming poetry.