Skip to content

Joe-Blabbah/Fiona

 
 

Repository files navigation

Fiona

Fiona is OGR's neat, nimble, no-nonsense API.

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 feature records as mappings from shapefiles or other GIS vector formats and write mappings as records to files using the same formats. That's all. There aren't any feature or geometry classes. Records and their geometries are just data.

For more details, see:

Dependencies

Fiona requires Python 2.6+ and GDAL 1.8+. To build from a source distribution or repository clone you will need a C compiler and GDAL and Python development headers and libraries. While there are no official binary distributions or Windows support at this time, you can find Windows installers at http://www.lfd.uci.edu/%7Egohlke/pythonlibs/#fiona.

Installation

Unix-like systems

Assuming you're using a virtualenv (if not, skip to the 4th command) and GDAL/OGR libraries, headers, and gdal-config program are installed to well known locations on your system via your system's package manager (brew install gdal using Homebrew on OS X), installation is this simple:

$ mkdir fiona_env
$ virtualenv fiona_env
$ source fiona_env/bin/activate
(fiona_env)$ pip install Fiona

If gdal-config is not available or if GDAL/OGR headers and libs aren't installed to a well known location, you must set include dirs, library dirs, and libraries options via the setup.cfg file or setup command line as shown below (using git):

(fiona_env)$ git clone git://github.com/Toblerity/Fiona.git
(fiona_env)$ cd Fiona
(fiona_env)$ python setup.py build_ext -I/path/to/gdal/include -L/path/to/gdal/lib -lgdal install

Windows

Binary installers are available at http://www.lfd.uci.edu/~gohlke/pythonlibs/#fiona and coming eventually to PyPI.

Usage

Records are read from and written to file-like Collection objects. Records are mappings modeled on the GeoJSON format. They don't have any spatial methods of their own, so if you want to do anything fancy with them you will probably need Shapely or something like it. Here is an example of using Fiona to read some records from one data file, change their geometry attributes, and write them to a new data file.

import fiona

# Open a file for reading. We'll call this the "source."
with fiona.open('docs/data/test_uk.shp', 'r') as source:

    # The file we'll write to, the "sink", must be initialized with a
    # coordinate system, a format driver name, and a record schema.
    sink_schema = source.schema.copy()
    sink_schema['geometry'] = 'Point'

    # Open an output file, using the same format driver and coordinate
    # reference system as the source.
    with fiona.open(
            'test_write.shp', 'w',
            crs=source.crs, driver=source.driver, schema=sink_schema,
            ) as sink:

        # Process only the records intersecting a box.
        for f in source.filter(bbox=(-5.0, 55.0, 0.0, 60.0)):

            # Get a point on the boundary of the record's geometry.
            f['geometry'] = {
                'type': 'Point',
                'coordinates': f['geometry']['coordinates'][0][0]}

            # Write the record out.
            sink.write(f)

    # The sink's contents are flushed to disk and the file is closed
    # when its ``with`` block ends. This effectively executes 
    # ``sink.flush(); sink.close()``.

Development and testing

Building from the source requires Cython. Tests require Nose. If the GDAL/OGR libraries, headers, and gdal-config program are installed to well known locations on your system (via your system's package manager), you can do this:

(fiona_env)$ git clone git://github.com/Toblerity/Fiona.git
(fiona_env)$ cd Fiona
(fiona_env)$ python setup.py build_ext --inplace
(fiona_env)$ python setup.py develop
(fiona_env)$ python setup.py nosetests

If you have a non-standard environment, you'll need to specify the include and lib dirs and GDAL library on the command line:

(fiona_env)$ python setup.py build_ext -I/path/to/gdal/include -L/path/to/gdal/lib -lgdal develop
(fiona_env)$ python setup.py nosetests