.. inclusion-marker-do-not-remove
PyGeoIf provides a GeoJSON-like protocol <https://gist.github.com/2217756>_
for geo-spatial (GIS) vector data.
Other Python programs and packages that you may have heard of that implement this protocol:
ArcPy <https://www.esri.com/about/newsroom/arcuser/geojson/>_descartes <https://docs.descarteslabs.com/>_PySAL <http://pysal.geodacenter.org/>_Shapely <https://github.com/Toblerity/Shapely>_pyshp <https://pypi.python.org/pypi/pyshp>_GeoPandas <https://geopandas.org/>_Karta <https://github.com/fortyninemaps/karta>_mapnik <https://github.com/mapnik/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 <https://python.org> and
PyPy <https://www.pypy.org/>, but it should work on alternative
Python implementations (that implement the language specification >=3.8) 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| |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
.. |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://pypi.python.org/pypi/pygeoif/ :alt: Downloads
You can install PyGeoIf from pypi using pip::
pip install pygeoif.. 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 <https://github.com/cleder/pygeoif/tree/main/tests>
directory which cover every aspect of pygeoif or in fastkml.
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 objectbounds: Returns a (minx, miny, maxx, maxy) tuple that bounds the object.wkt: Returns the 'Well Known Text' representation of the objectFor 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.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
1.0A 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.
Attributesexterior : LinearRing The ring which bounds the positive space of the polygon. interiors : sequence A sequence of rings which bound all existing holes. maybe_valid: boolean When a polygon has obvious problems such as self crossing lines or holes that are outside the exterior bounds this will return False. Even if this returns True the geometry may still be invalid, but if this returns False you do have a problem.
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.
Attributesgeoms : sequence A sequence of LineStrings
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).
Attributesgeoms : 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.
Attributesgeometry : 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
Attributesfeatures: 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"
black pygeoif
ruff pygeoif
flake8 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