======
README
======

Fiona is OGR's neater API – sleek and elegant on the outside, indomitable power
on the inside.

Fiona provides a minimal, uncomplicated Python interface to the open source GIS
community's most trusted geodata access library and integrates readily with
other Python GIS packages such as pyproj_, Rtree_, and Shapely_.

How minimal? Fiona can read features as mappings from shapefiles or other GIS
vector formats and write mappings as features to files using the same formats.
That's all. There aren't any feature or geometry classes. Features and their
geometries are just data.

Dependencies
============

Fiona requires Python 2.6+ and libgdal 1.3.2+.

Installation
============

Assuming you will install in a virtual environment and gdal-config_ is
properly installed::

  $ virtualenv .
  $ source bin/activate
  (Fiona)$ pip install -d Fiona Fiona-0.5.tar.gz
  (Fiona)$ cd Fiona
  (Fiona)$ python setup.py build_ext $(gdal-config --cflags) $(gdal-config --libs) install

If gdal-config is not available or if GDAL/OGR headers and libs aren't
installed to a well known location, you must pass the build options
and locations in using setup arguments as shown above::

  (Fiona)$ python setup.py build_ext -I/path/to/include -L/path/to/lib -lgdal install
Usage
=====

Collections are much like ``file`` objects. Features are mappings modeled on
the GeoJSON format and if you want to do anything fancy with them you will
probably need Shapely or something like it::

  from fiona import collection
  from shapely import asShape, mapping

  # Open a source of features
  with collection("docs/data/test_uk.shp", "r") as source:
  
      # Define a schema for the feature sink
      schema = input.schema.copy()
      schema['geometry'] = 'Point'
      
      # Open a new sink for features
      with collection(
              "test_write.shp", "w", driver="ESRI Shapefile", schema=schema
              ) as sink:
          
          # Process only the features intersecting a box
          for f in source.filter(bbox=(-5.0, 55.0, 0.0, 60.0)):
          
              # Get their centroids using Shapely
              f['geometry'] = mapping(asShape(f['geometry']).centroid)
              
              # Stage feature for writing
              sink.write(f)
              
      # The sink shapefile is written to disk when its ``with`` block ends

Development and testing
=======================

Building from the source requires Cython. Tests require Nose. From the
distribution root::

  $ virtualenv .
  $ source bin/activate
  (Fiona)$ ./cypsrc
  (Fiona)$ python setup.py build_ext $(gdal-config --cflags) $(gdal-config --libs) develop
  (Fiona)$ python setup.py $(gdal-config --cflags) $(gdal-config --libs) nosetests



.. _libgdal: http://www.gdal.org
.. _pyproj: http://pypi.python.org/pypi/pyproj/
.. _Rtree: http://pypi.python.org/pypi/Rtree/
.. _Shapely: http://pypi.python.org/pypi/Shapely/
.. _gdal-config: http://www.gdal.org/gdal-config.html

