PyGeoIf provides a GeoJSON-like protocol for geo-spatial (GIS) vector data.

see https://gist.github.com/2217756

Other Python programs and packages that you may have heard of already implement this protocol:

• ArcPy http://help.arcgis.com/en/arcgisdesktop/
• descartes https://bitbucket.org/sgillies/descartes/
• geojson http://pypi.python.org/pypi/geojson/
• PySAL http://pysal.geodacenter.org/
• Shapely https://github.com/Toblerity/Shapely
• pyshp https://pypi.python.org/pypi/pyshp

So when you want to write your own geospatial library with support for this protocol you may use pygeoif as a starting point and build your functionality on top of it

You may think of pygeoif as a 'shapely ultralight' which lets you construct geometries and perform very basic operations like reading and writing geometries from/to WKT, constructing line strings out of points, polygons from linear rings, multi polygons from polygons, etc. It was inspired by shapely and implements the geometries in a way that when you are familiar with shapely you feel right at home with pygeoif

It was written to provide clean and python only geometries for fastkml

PyGeoIf is continually tested with Travis CI

>>> from pygeoif import geometry >>> p = geometry.Point(1,1) >>> p.__geo_interface__ {'type': 'Point', 'coordinates': (1.0, 1.0)} >>> print p POINT (1.0 1.0) >>> p1 = geometry.Point(0,0) >>> l = geometry.LineString([p,p1]) >>> l.bounds (0.0, 0.0, 1.0, 1.0) >>> dir(l) ['__class__', '__delattr__', '__dict__', '__doc__', '__format__', '__geo_interface__', '__getattribute__', '__hash__', '__init__', '__module__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_coordinates', '_geoms', '_type', 'bounds', 'coords', 'geom_type', 'geoms', 'to_wkt'] >>> print l LINESTRING (1.0 1.0, 0.0 0.0)

You find more examples in the test_main.py file which cover every aspect of pygeoif or in fastkml.

All classes implement the attribute:

• __geo_interface__: as dicussed above

All geometry classes implement the attributes:

• geom_type: Returns a string specifying the Geometry Type of the object
• bounds: Returns a (minx, miny, maxx, maxy) tuple (float values) that bounds the object.
• wkt: Returns the 'Well Known Text' representation of the object

and the method:

• to_wkt which also prints the object

Base class for Geometry, Feature, and FeatureCollection

Base class for geometry objects. Inherits from Geoobject.

A zero dimensional geometry

A point has zero length and zero area.

x, y, z : float

Coordinate values

>>> p = Point(1.0, -1.0) >>> print p POINT (1.0000000000000000 -1.0000000000000000) >>> p.y -1.0 >>> p.x 1.0

A one-dimensional figure comprising one or more line segments

A LineString has non-zero length and zero area. It may approximate a curve and need not be straight. Unlike a LinearRing, a LineString is not closed.

geoms : sequence

A sequence of Points

A closed one-dimensional geometry comprising one or more line segments

A LinearRing that crosses itself or touches itself at a single point is invalid and operations on it may fail.

A Linear Ring is self closing

A two-dimensional figure bounded by a linear ring

A polygon has a non-zero area. It may have one or more negative-space "holes" which are also bounded by linear rings. If any rings cross each other, the geometry is invalid and operations on it may fail.

exterior : LinearRing

The ring which bounds the positive space of the polygon.

interiors : sequence

A sequence of rings which bound all existing holes.

A collection of one or more points

geoms : sequence

A sequence of Points

A collection of one or more line strings

A MultiLineString has non-zero length and zero area.

geoms : sequence

A sequence of LineStrings

A collection of one or more polygons

geoms : sequence

A sequence of Polygon instances

A heterogenous collection of geometries (Points, LineStrings, LinearRings and Polygons)

geoms : sequence

A sequence of geometry instances

Please note: GEOMETRYCOLLECTION isn't supported by the Shapefile format. And this sub-class isn't generally supported by ordinary GIS sw (viewers and so on). So it's very rarely used in the real GIS professional world.

>>> from pygeoif import geometry >>> p = geometry.Point(1.0, -1.0) >>> p2 = geometry.Point(1.0, -1.0) >>> geoms = [p, p2] >>> c = geometry.GeometryCollection(geoms) >>> c.__geo_interface__ {'type': 'GeometryCollection', 'geometries': [{'type': 'Point', 'coordinates': (1.0, -1.0)},/ {'type': 'Point', 'coordinates': (1.0, -1.0)}]} >>> [geom for geom in geoms] [Point(1.0, -1.0), Point(1.0, -1.0)]

Aggregates a geometry instance with associated user-defined properties.

geometry : object

A geometry instance

properties : dict

A dictionary linking field keys with values associated with with geometry instance

>>> p = Point(1.0, -1.0) >>> props = {'Name': 'Sample Point', 'Other': 'Other Data'} >>> a = Feature(p, props) >>> a.properties {'Name': 'Sample Point', 'Other': 'Other Data'} >>> a.properties['Name'] 'Sample Point'

A heterogenous collection of Features

features: sequence

A sequence of feature instances

>>> from pygeoif import geometry >>> p = geometry.Point(1.0, -1.0) >>> props = {'Name': 'Sample Point', 'Other': 'Other Data'} >>> a = geometry.Feature(p, props) >>> p2 = geometry.Point(1.0, -1.0) >>> props2 = {'Name': 'Sample Point2', 'Other': 'Other Data2'} >>> b = geometry.Feature(p2, props2) >>> features = [a, b] >>> c = geometry.FeatureCollection(features) >>> c.__geo_interface__ {'type': 'FeatureCollection', 'features': [{'geometry': {'type': 'Point', 'coordinates': (1.0, -1.0)},/ 'type': 'Feature', 'properties': {'Other': 'Other Data', 'Name': 'Sample Point'}},/ {'geometry': {'type': 'Point', 'coordinates': (1.0, -1.0)}, 'type': 'Feature',/ 'properties': {'Other': 'Other Data2', 'Name': 'Sample Point2'}}]} >>> [feature for feature in c] [<Feature Instance Point geometry 2 properties>, <Feature Instance Point geometry 2 properties>]

Create a pygeoif feature from an object that provides the __geo_interface__

>>> from shapely.geometry import Point >>> from pygeoif import geometry >>> geometry.as_shape(Point(0,0)) <pygeoif.geometry.Point object at 0x...>

Create a geometry from its WKT representation

>>> p = geometry.from_wkt('POINT (0 1)') >>> print p POINT (0.0 1.0)

Return the signed area enclosed by a ring using the linear time algorithm at http://www.cgafaq.info/wiki/Polygon_Area. A value >= 0 indicates a counter-clockwise oriented ring.

Returns a copy of the polygon with exterior in counter-clockwise and interiors in clockwise orientation for sign=1.0 and the other way round for sign=-1.0

Returns the __geo_interface__ dictionary

You can install PyGeoIf from pypi using pip:

pip install pygeoif

In order to provide a Travis-CI like testing of the PyGeoIf package during development, you can use tox (pip install tox) to evaluate the tests on all supported Python interpreters which you have installed on your system.

You can run the tests with tox --skip-missin-interpreters and are looking for output similar to the following:

______________________________________________________ summary ______________________________________________________
SKIPPED:  py26: InterpreterNotFound: python2.6
  py27: commands succeeded
SKIPPED:  py32: InterpreterNotFound: python3.2
SKIPPED:  py33: InterpreterNotFound: python3.3
  py34: commands succeeded
SKIPPED:  pypy: InterpreterNotFound: pypy
SKIPPED:  pypy3: InterpreterNotFound: pypy3
  congratulations :)

You are primarily looking for the congratulations :) line at the bottom, signifying that the code is working as expected on all configurations available.