migration and tips on writing code for both python lines and audiences regardless of which version or versions you choose to focus on firstyour skills will transfer directly to wherever your python work leads you about the xsthroughout this book" xand " xare used to refer collectively to all releases in these two lines for instance includes through and future releases means all from through (and presumably no othersmore specific releases are mentioned when topic applies to it only ( ' set literals and ' launcher and namespace packagesthis notation may occasionally be too broad --some features labeled here may not be present in early releases rarely used today--but it accommodates line that has already spanned years the label is more easily and accurately applied to this younger five-year-old line this book' prerequisites and effort it' impossible to give absolute prerequisites for this bookbecause its utility and value can depend as much on reader motivation as on reader background both true beginners and crusty programming veterans have used this book successfully in the past if you are motivated to learn pythonand willing to invest the time and focus it requiresthis text will probably work for you just how much time is required to learn pythonalthough this will vary per learnerthis book tends to work best when read some readers may use this book as an ondemand reference resourcebut most people seeking python mastery should expect to spend at least weeks and probably months going through the material heredepending on how closely they follow along with its examples as mentionedit' roughly equivalent to full-semester course on the python language itself that' the estimate for learning just python itself and the software skills required to use it well though this book may suffice for basic scripting goalsreaders hoping to pursue software development at large as career should expect to devote additional time after this book to large-scale project experienceand possibly to follow-up texts such as programming python the standard disclaimeri wrote this and another book mentioned earlierwhich work together as setlearning python for language fundamentalsprogramming python for applications basicsand python pocket reference as companion to the other two all three derive from ' original and broad programming python encourage you to explore the many python books available today ( stopped counting at at amazon com just now because there was no end in sightand this didn' include related subjects like djangomy own publisher has recently produced python-focused books on instrumentationdata miningapp enginenumeric analysisnatural language processingmongodbawsand more--specific domains you may wish to explore once you've mastered python language fundamentals here the python story today is far too rich for any one book to address alone preface xxxix