Foreword

“Micro” does not mean that your whole web application has to fit into a singlePython file (although it certainly can), nor does it mean that Flask is lackingin functionality. The “micro” in microframework means Flask aims to keep thecore simple but extensible. Flask won’t make many decisions for you, such aswhat database to use. Those decisions that it does make, such as whattemplating engine to use, are easy to change. Everything else is up to you, sothat Flask can be everything you need and nothing you don’t.

Flask has many configuration values, with sensible defaults, and a fewconventions when getting started. By convention, templates and staticfiles are stored in subdirectories within the application’s Pythonsource tree, with the names and staticrespectively. While this can be changed, you usually don’t have to,especially when getting started.

As your codebase grows, you are free to make the design decisions appropriatefor your project. Flask will continue to provide a very simple glue layer tothe best that Python has to offer. You can implement advanced patterns inSQLAlchemy or another database tool, introduce non-relational data persistenceas appropriate, and take advantage of framework-agnostic tools built for WSGI,the Python web interface.

Continue to Installation, the , or theForeword for Experienced Programmers.