on these subjects other random bits naturallythere were additional smaller changes made along the way for exampletkinter' grid method is used instead of pack for layout of most input formsbecause it yields more consistent layout on platforms where label font sizes don' match up with entry widget height (including on windows netbook laptopthis edition' development machinethere' also new material scattered throughoutincluding new exploration of redirecting streams to sockets in the internet parta new threaded and unicode-aware "grepdialog and process-wide change tests on exit in the pyedit exampleand other things you are probably better off uncovering along the way than reading further about in this preface also finally replaced some remaining "#comment blocks at the top of source files with docstrings (evenfor consistencyin scripts not meant to be importedthough some "#lines are retained in larger examples to offset the text)changed few lingering "while to "while true"use +more oftenand cleaned up few other cases of now-dated coding patterns old habits may die hardbut such updates make the examples both more functional and more representative of common practice today although new topics were addedall toldfour were cut outright (the nontechnical introductionone of the system example advanced internet topicsand one integration some additional examples and material were trimmed (including pyform and pytree)and focus was deliberately restricted to python and application fundamentals to conserve space what' leftthenthe combined effect of all the changes just outlined is that this edition more concisely and sharply reflects its core focus--that of tutorial introduction to ways to apply python in common programming domains neverthelessas you can tell from this book' page countit is still substantial and in-depth bookdesigned to be first step on your path to mastering realistic applications of python contrary to recent trends (and at some risk of being branded heretic) firmly believe that the job of books like this one is to elevate their readersnot pander to them lowering the intellectual bar does disservice both to readers and to the fields in which they hope to work while that means you won' find as many cartoons in this book as in somethis book also won' insult you by emphasizing entertainment at the expense of technical depth insteadthe goal of my books is to impart sophisticated concepts in satisfying and substantive way and to equip you with the tools you'll need in the real world of software development xxx preface