Author Introduction =================== Welcome to "The :mod:`repoze.bfg` Web Application Framework". In this introduction, I'll describe the audience for this book, I'll provide some context regarding the genesis of :mod:`repoze.bfg`, and I'll thank some important people. I hope you enjoy both this book and the software it documents. I've had a blast writing both. Audience -------- This book is aimed primarily at a reader that has the following attributes: - At least a moderate amount of :term:`Python` experience. - A familiarity with web protocols such as HTTP and CGI. If you fit into both of these categories, you're in the direct target audience for this book. But don't worry, even if you have no experience with Python or the web, both are easy to pick up "on the fly". Python is an *excellent* language in which to write applications; becoming productive in Python is almost mind-blowingly easy. If you already have experience in another language such as Java, Visual Basic, Perl, Ruby, or even C/C++, learning Python will be a snap; it should take you no longer than a couple of days to become modestly productive. If you don't have previous programming experience, it will be slightly harder, and it will take a little longer, but you'd be hard-pressed to find a better "first language." Web technology familiarity is assumed in various places within the book. For example, the book describes various interactions in terms of the HTTP protocol, but it does not describe how the HTTP protocol works in detail. Like any good framework, though, :mod:`repoze.bfg` shields you from needing to know the gory details of web protocols such as HTTP, and you can usually skip such descriptions without becoming "blocked," although you may lack some fundamental understanding of how it works "under the hood" as a result. The Genesis of :mod:`repoze.bfg` -------------------------------- I wrote :mod:`repoze.bfg` after many years of writing applications using :term:`Zope`. Zope provided me with a lot of mileage: it wasn't until almost a decade of succesfully creating applications using Zope that I decided to write a different web framework. Although :mod:`repoze.bfg` takes inspiration from a variety of web frameworks, it owes more of its core design to Zope than any other. The "Repoze" brand existed before :mod:`repoze.bfg`. One of the first packages developed as part of the Repoze brand was a package named :mod:`repoze.zope2`. This was a package that allowed Zope 2 applications to run under a :term:`WSGI` server without modification. Zope 2 did not have reasonable WSGI support at the time. During the development of the :mod:`repoze.zope2` package, I found that replicating the Zope 2 "publisher" -- the machinery that maps URLs to code -- was time-consuming and fiddly. Zope 2 had evolved over many years, and emulating all of its edge cases was extremely difficult. I finished the :mod:`repoze.zope2` package, and it emulates the normal Zope 2 publisher pretty well. But during its development, it became clear that Zope 2 had simply begun to exceed my tolerance for complexity, and I began to look around for simpler options. I considered the using Zope 3 application server machinery, but it turned out that it had become more indirect than the Zope 2 machinery it aimed to replace, which didn't fulfill the goal of simplification. I also considered using Django and Pylons, but neither of those frameworks offer much along the axes of traversal, contextual declarative security, or application extensibility; these were features I had become accustomed to as a Zope developer. I decided that in the long term, creating a simpler, legacy-free framework that retained features I had become accustomed to when developing Zope applications was a more reasonable idea than continuing to use any Zope publisher or living with the limitations and unfamiliarities of a different framework. The result is what is now :mod:`repoze.bfg`. It is immodest to say so, but I believe :mod:`repoze.bfg` has turned out to be the very best Python web framework available today, bar none. It combines all the "good parts" from other web frameworks into a cohesive whole that is reliable, down-to-earth, flexible, speedy, and well-documented. Thanks ------ This book is dedicated to my grandmother, Dorothy Phillips, who gave me my first typewriter, and my mother, Donelle Duffy, who bought me my first computer (a VIC-20). Thanks to the following people for providing expertise, resources, and software. Without the help of these folks, neither this book nor the software which it details would exist: Paul Everitt, Tres Seaver, Andrew Sawyers, Malthe Borch, Carlos de la Guardia, Georg Brandl, Simon Oram of Electrosoup, Ian Bicking of the Open Planning Project, Jim Fulton of Zope Corporation, Tom Moroz of the Open Society Institute, and Todd Koym of Environmental Health Sciences. Special thanks to Guido van Rossum and Tim Peters for Python. Special thanks also to Tricia for putting up with me.