databases and persistence "give me an order of persistencebut hold the picklesso far in this bookwe've used python in the system programminggui developmentand internet scripting domains--three of python' most common applicationsand representative of its use as an application programming language at large in the next four we're going to take quick look at other major python programming topicspersistent datadata structure techniquestext and language processingand python/ integration these four topics are not really application areas themselvesbut they are techniques that span domains the database topics in this for instancecan be applied on the webin desktop gui applicationsand so on text processing is similarly general tool moreovernone of these final four topics is covered exhaustively (each could easily fill book alone)but we'll sample python in action in these domains and highlight their core concepts and tools if any of these spark your interestadditional resources are readily available in the python world persistence options in python in this our focus is on persistent data--the kind that outlives program that creates it that' not true by default for objects script constructsof coursethings like listsdictionariesand even class instance objects live in your computer' memory and are lost as soon as the script ends to make data live longerwe need to do something special in python programmingthere are today at least six traditional ways to save information in between program executionsflat files text and bytes stored directly on your computer dbm keyed files keyed access to strings stored in dictionary-like files