Applications that work with bill payments and receipts, as well as the delivery and inventory of items, generally require the use of barcodes or QR Codes. The latter is used in even broader scenarios since the QR Code can store more information than a simple bar code. Thus, it is important to have the ability to generate barcodes and QR Codes or read the data stored in them from an image or a PDF. This article will show you how to do this using Python and some of its free libraries.