Fiona provides uncomplicated Python interfaces to functions in OGR, the best open source C/C++ library for reading and writing geographic vector data.
Fiona is designed to be simple and dependable. It focuses on reading and writing data in standard Python IO style, and relies upon familiar Python types and protocols such as files, dictionaries, mappings, and iterators instead of classes specific to OGR. Fiona can read and write real-world data using multi-layered GIS formats and zipped virtual file systems and integrates readily with other Python GIS packages such as pyproj, Rtree, and Shapely.
For more details, see:
- Fiona home page
- Fiona docs and manual
- Fiona examples
Fiona requires Python 2.6, 2.7, or 3.3 and GDAL/OGR 1.8+. To build from a source distribution or repository copy you will need a C compiler and GDAL and Python development headers and libraries (libgdal1-dev for Debian/Ubuntu, gdal-dev for CentOS/Fedora).
The popular Kyngchaos GDAL frameworks will satisfy
the dependency for OS X. Fiona's author uses Homebrew (brew install gdal)
on OS X.
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.
Fiona depends on the modules six and argparse. The latter is standard
in Python 2.7+. Easy_install and pip will fetch these requirements for you, but
users installing Fiona from a Windows installer must get them separately.
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
Binary installers are available at http://www.lfd.uci.edu/~gohlke/pythonlibs/#fiona and coming eventually to PyPI.
Records are read from and written to file-like Collection objects
returned from the fiona.open() function. 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') 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.
# We can get initial values from the open collection's ``meta``
# property and then modify them as desired.
meta = source.meta
meta['schema']['geometry'] = 'Point'
# Open an output file, using the same format driver and coordinate
# reference system as the source. The ``meta`` mapping fills in
# the keyword parameters of fiona.open().
with fiona.open('test_write.shp', 'w', **meta) 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()``.Collections can also be made from single layers within multilayer files or
directories of data. The target layer is specified by name or by its integer
index within the file or directory. The fiona.listlayers() function
provides an index ordered list of layer names.
for layername in fiona.listlayers('docs/data'):
with fiona.open('docs/data', layer=layername) as c:
print(layername, len(c))
# Output:
# test_uk 48Layer can also be specified by index. In this case, layer=0 and
layer='test_uk' specify the same layer in the data file or directory.
for i, layername in enumerate(fiona.listlayers('docs/data')):
with fiona.open('docs/data', layer=i) as c:
print(i, layername, len(c))
# Output:
# 0 test_uk 48Multilayer data can be written as well. Layers must be specified by name when writing.
with open('docs/data/test_uk.shp') as c:
meta = c.meta
f = next(c)
with fiona.open('/tmp/foo', 'w', layer='bar', **meta) as c:
c.write(f)
print(fiona.listlayers('/tmp/foo'))
# Output: ['bar']
with fiona.open('/tmp/foo', layer='bar') as c:
print(len(c))
f = next(c)
print(f['geometry']['type'])
print(f['properties'])
# Output:
# 1
# Polygon
# {'FIPS_CNTRY': 'UK', 'POP_CNTRY': 60270708.0, 'CAT': 232.0,
# 'AREA': 244820.0, 'CNTRY_NAME': 'United Kingdom'}A view of the /tmp/foo directory will confirm the creation of the new files.
$ ls /tmp/foo
bar.cpg bar.dbf bar.prj bar.shp bar.shxZip and Tar archives can be treated as virtual filesystems and Collections can be made from paths and layers within them. In other words, Fiona lets you read and write zipped Shapefiles.
for i, layername in enumerate(
fiona.listlayers(
'/',
vfs='zip://docs/data/test_uk.zip')):
with fiona.open(
'/',
vfs='zip://docs/data/test_uk.zip',
layer=i) as c:
print(i, layername, len(c))
# Output:
# 0 test_uk 48Fiona installs a script named "dumpgj". It converts files to GeoJSON with JSON-LD context as an option.
$ dumpgj --help
usage: dumpgj [-h] [-d] [-n N] [--compact] [--encoding ENC]
[--record-buffered] [--ignore-errors] [--use-ld-context]
[--add-ld-context-item TERM=URI]
infile [outfile]
Serialize a file's records or description to GeoJSON
positional arguments:
infile input file name
outfile output file name, defaults to stdout if omitted
optional arguments:
-h, --help show this help message and exit
-d, --description serialize file's data description (schema) only
-n N, --indent N indentation level in N number of chars
--compact use compact separators (',', ':')
--encoding ENC Specify encoding of the input file
--record-buffered Economical buffering of writes at record, not
collection (default), level
--ignore-errors log errors but do not stop serialization
--use-ld-context add a JSON-LD context to JSON output
--add-ld-context-item TERM=URI
map a term to a URI and add it to the output's JSON LD
context
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 develop (fiona_env)$ 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)$ nosetests