"and now for something completely different this book explores ways to apply the python programming language in common application domains and realistically scaled tasks it' about what you can do with the language once you've mastered its fundamentals this book assumes you are relatively new to each of the application domains it covers-guisthe internetdatabasessystems programmingand so on--and presents each from the ground upin tutorial fashion along the wayit focuses on commonly used tools and librariesrather than language fundamentals the net result is resource that provides readers with an in-depth understanding of python' roles in practicalrealworld programming work as subthemethis book also explores python' relevance as software development tool-- role that many would classify as well beyond those typically associated with "scripting in factmany of this book' examples are scaled specifically for this purposeamong thesewe'll incrementally develop email clients that top out at thousands of lines of code programming at this full scale will always be challenging workbut we'll find that it' also substantially quicker and easier when done with python this fourth edition has been updated to present the languagelibrariesand practice of python specificallyits examples use python --the most recent version of python at the time of writing--and its major examples were tested successfully under the third alpha release of python just prior to publicationbut they reflect the version of the language common to the entire line this edition has also been reorganized in ways that both streamline some of its former material and allow for coverage of newly emerged tools and topics because this edition' readership will include both newcomers as well as prior edition veteransi want to use this preface to expand on this book' purpose and scope before we jump into code xxiii