Introduction ============ .. inclusion-marker-do-not-remove PyGeoIf provides a `GeoJSON-like protocol `_ for geo-spatial (GIS) vector data. Other Python programs and packages that you may have heard of that implement this protocol: * `ArcPy `_ * `descartes `_ * `PySAL `_ * `Shapely `_ * `pyshp `_ * `GeoPandas `_ * `Karta `_ * `mapnik `_ 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. It has no requirements outside the Python standard library and is therefore easy to integrate into your project. It is tested on `CPython `_, `PyPy `_ and `GraalPy `_, but it should work on alternative Python implementations (that implement the language specification *>=3.9*) as well. 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 pygeoif, you will feel right at home with shapely or the other way round. It provides Hypothesis strategies for all geometries for property based testing with Hypothesis_. It was written to provide clean and python only geometries for fastkml_ |doc| |test| |cov| |hypothesis| |black| |mypy| |openhub| |factor| |commit| |py| |implement| |latest| |conda| |license| |downloads| .. |doc| image:: https://readthedocs.org/projects/pygeoif/badge/?version=latest :target: https://pygeoif.readthedocs.io/en/latest/?badge=latest :alt: Documentation .. |test| image:: https://github.com/cleder/pygeoif/actions/workflows/run-all-tests.yml/badge.svg?branch=main :target: https://github.com/cleder/pygeoif/actions/workflows/run-all-tests.yml :alt: GitHub Actions .. |cov| image:: https://codecov.io/gh/cleder/pygeoif/branch/main/graph/badge.svg?token=2EfiwBXs9X :target: https://codecov.io/gh/cleder/pygeoif :alt: Codecov .. |hypothesis| image:: https://img.shields.io/badge/hypothesis-tested-brightgreen.svg :alt: Tested with Hypothesis :target: https://hypothesis.readthedocs.io .. |black| image:: https://img.shields.io/badge/code_style-black-000000.svg :target: https://github.com/psf/ :alt: Black .. |mypy| image:: https://img.shields.io/badge/type_checker-mypy-blue :target: http://mypy-lang.org/ :alt: Mypy .. |openhub| image:: https://www.openhub.net/p/pygeoif/widgets/project_thin_badge.gif :target: https://www.openhub.net/p/pygeoif/ :alt: Openhub .. |factor| image:: https://www.codefactor.io/repository/github/cleder/pygeoif/badge/main :target: https://www.codefactor.io/repository/github/cleder/pygeoif/overview/main :alt: CodeFactor .. |commit| image:: https://img.shields.io/badge/pre--commit-enabled-brightgreen?logo=pre-commit :target: https://github.com/pre-commit/pre-commit :alt: pre-commit .. |py| image:: https://img.shields.io/pypi/pyversions/pygeoif.svg :target: https://pypi.python.org/pypi/pygeoif/ :alt: Supported Python versions .. |conda| image:: https://img.shields.io/conda/vn/conda-forge/pygeoif.svg :target: https://anaconda.org/conda-forge/pygeoif :alt: Conda Version .. |implement| image:: https://img.shields.io/pypi/implementation/pygeoif.svg :target: https://pypi.python.org/pypi/pygeoif/ :alt: Supported Python implementations .. |latest| image:: https://img.shields.io/pypi/v/pygeoif.svg :target: https://pypi.python.org/pypi/pygeoif/ :alt: Latest Version .. |license| image:: https://img.shields.io/pypi/l/pygeoif.svg :target: https://pypi.python.org/pypi/pygeoif/ :alt: License .. |downloads| image:: https://img.shields.io/pypi/dm/pygeoif.svg :target: https://www.pepy.tech/projects/pygeoif :alt: Downloads Installation ------------ You can install PyGeoIf from pypi using pip:: pip install pygeoif Example ======== .. code-block:: pycon >>> from pygeoif import geometry >>> p = geometry.Point(1,1) >>> p.__geo_interface__ {'type': 'Point', 'bbox': (1, 1, 1, 1), 'coordinates': (1, 1)} >>> print(p) POINT (1 1) >>> p Point(1, 1) >>> l = geometry.LineString([(0.0, 0.0), (1.0, 1.0)]) >>> l.bounds (0.0, 0.0, 1.0, 1.0) >>> print(l) LINESTRING (0.0 0.0, 1.0 1.0) You find more examples in the `tests `_ directory which cover every aspect of pygeoif or in fastkml_. Classes ======== All classes implement the attribute: * ``__geo_interface__``: as discussed above, an interface to GeoJSON_. 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 that bounds the object. * ``wkt``: Returns the 'Well Known Text' representation of the object For two-dimensional geometries the following methods are implemented: * ``convex_hull``: Returns a representation of the smallest convex Polygon containing all the points in the object unless the number of points in the object is less than three. For two points, the convex hull collapses to a LineString; for 1, a Point. For three dimensional objects only their projection in the xy plane is taken into consideration. Empty objects without coordinates return ``None`` for the convex_hull. Point ----- A zero dimensional geometry A point has zero length and zero area. A point cannot be empty. Attributes ~~~~~~~~~~~ x, y, z : float Coordinate values Example ~~~~~~~~ .. code-block: pycon >>> from pygeoif import Point >>> p = Point(1.0, -1.0) >>> print(p) POINT (1.0 -1.0) >>> p.y -1.0 >>> p.x 1.0 LineString ----------- 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. Attributes ~~~~~~~~~~~ geoms : sequence A sequence of Points LinearRing ----------- 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 LinearRing is self closing. Polygon -------- 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. Attributes ~~~~~~~~~~~ exterior : LinearRing The ring which bounds the positive space of the polygon. interiors : sequence A sequence of rings which bound all existing holes. MultiPoint ---------- A collection of one or more points. Attributes ~~~~~~~~~~~ geoms : sequence A sequence of Points. MultiLineString ---------------- A collection of one or more line strings. A MultiLineString has non-zero length and zero area. Attributes ~~~~~~~~~~~ geoms : sequence A sequence of LineStrings MultiPolygon ------------- A collection of one or more polygons. Attributes ~~~~~~~~~~~~~ geoms : sequence A sequence of `Polygon` instances GeometryCollection ------------------- A heterogenous collection of geometries (Points, LineStrings, LinearRings and Polygons). Attributes ~~~~~~~~~~~ geoms : sequence A sequence of geometry instances Please note: ``GEOMETRYCOLLECTION`` isn't supported by the Shapefile or GeoJSON_ 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. Example ~~~~~~~~ .. code-block:: pycon >>> 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) >>> [geom for geom in geoms] [Point(1.0, -1.0), Point(1.0, -1.0)] Feature ------- Aggregates a geometry instance with associated user-defined properties. Attributes ~~~~~~~~~~~ geometry : object A geometry instance properties : dict A dictionary linking field keys with values associated with with geometry instance Example ~~~~~~~~ .. code-block:: pycon >>> from pygeoif import Point, Feature >>> 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' FeatureCollection ----------------- A heterogenous collection of Features Attributes ~~~~~~~~~~~ features: sequence A sequence of feature instances Example ~~~~~~~~ .. code-block:: pycon >>> from pygeoif import Point, Feature, FeatureCollection >>> p = Point(1.0, -1.0) >>> props = {'Name': 'Sample Point', 'Other': 'Other Data'} >>> a = Feature(p, props) >>> p2 = Point(1.0, -1.0) >>> props2 = {'Name': 'Sample Point2', 'Other': 'Other Data2'} >>> b = Feature(p2, props2) >>> features = [a, b] >>> c = FeatureCollection(features) >>> [feature for feature in c] [Feature(Point(1.0, -1.0), {'Name': 'Sample Point', 'Other': 'Other Data'},...] Functions ========= shape -------- Create a pygeoif feature from an object that provides the ``__geo_interface__`` or any GeoJSON_ compatible dictionary. .. code-block:: pycon >>> from shapely.geometry import Point >>> from pygeoif import geometry, shape >>> shape(Point(0,0)) Point(0.0, 0.0) from_wkt --------- Create a geometry from its WKT representation .. code-block:: pycon >>> from pygeoif import from_wkt >>> p = from_wkt('POINT (0 1)') >>> print(p) POINT (0.0 1.0) signed_area ------------ Return the signed area enclosed by a ring. A value >= 0 indicates a counter-clockwise oriented ring. orient ------- Returns a copy of a polygon with exteriors and interiors in the right orientation. if ccw is True than the exterior will be in counterclockwise orientation and the interiors will be in clockwise orientation, or the other way round when ccw is False. box --- Return a rectangular polygon with configurable normal vector. mapping ------- Return the ``__geo_interface__`` dictionary. Development =========== Clone this repository, create a virtualenv with Python 3.8 or later with ``python3 -m venv .venv`` and activate it with ``source .venv/bin/activate``. Then install the requirements with ``pip install -e ".[dev]"``. pre-commit ---------- Install the ``pre-commit`` hook with:: pip install pre-commit pre-commit install and check the code with:: pre-commit run --all-files Testing ------- Run the unit and static tests with:: pytest tests pytest --doctest-glob="README.rst" ruff check pygeoif ruff fmt pygeoif mypy pygeoif Acknowledgments ================ The tests were improved with mutmut_ which discovered some nasty edge cases. .. _mutmut: https://github.com/boxed/mutmut .. _GeoJSON: https://geojson.org/ .. _fastkml: http://pypi.python.org/pypi/fastkml/ .. _Hypothesis: https://hypothesis.works