shapely 1.6.3

Geometric objects, predicates, and operations

Manipulation and analysis of geometric objects in the Cartesian plane.

Shapely is a BSD-licensed Python package for manipulation and analysis of planar geometric objects. It is based on the widely deployed GEOS (the engine of PostGIS) and JTS (from which GEOS is ported) libraries. Shapely is not concerned with data formats or coordinate systems, but can be readily integrated with packages that are. For more details, see:

• Shapely GitHub repository

• Shapely documentation and manual

Requirements

Shapely 1.6 requires

• Python >=2.6 (including Python 3.x)

• GEOS >=3.3

Installing Shapely 1.6

Shapely may be installed from a source distribution or one of several kinds of built distribution.

Built distributions

Windows users have two good installation options: the wheels at http://www.lfd.uci.edu/~gohlke/pythonlibs/#shapely and the Anaconda platform’s [conda-forge](https://conda-forge.github.io/) channel.

OS X and Linux users can get Shapely wheels with GEOS included from the Python Package Index with a recent version of pip (8+):

$ pip install shapely

A few extra speedups that require Numpy can be had by running

$ pip install shapely[vectorized]

Shapely is available via system package management tools like apt, yum, and Homebrew, and is also provided by popular Python distributions like Canopy and Anaconda.

Source distributions

If you want to build Shapely from source for compatibility with other modules that depend on GEOS (such as cartopy or osgeo.ogr) or want to use a different version of GEOS than the one included in the project wheels you should first install the GEOS library, Cython, and Numpy on your system (using apt, yum, brew, or other means) and then direct pip to ignore the binary wheels.

$ pip install shapely --no-binary shapely

If you’ve installed GEOS to a standard location, the geos-config program will be used to get compiler and linker options. If geos-config is not on your executable, it can be specified with a GEOS_CONFIG environment variable, e.g.:

$ GEOS_CONFIG=/path/to/geos-config pip install shapely

Usage

Here is the canonical example of building an approximately circular patch by buffering a point.

>>> from shapely.geometry import Point
>>> patch = Point(0.0, 0.0).buffer(10.0)
>>> patch
<shapely.geometry.polygon.Polygon object at 0x...>
>>> patch.area
313.65484905459385

See the manual for comprehensive usage snippets and the dissolve.py and intersect.py examples.

Integration

Shapely does not read or write data files, but it can serialize and deserialize using several well known formats and protocols. The shapely.wkb and shapely.wkt modules provide dumpers and loaders inspired by Python’s pickle module.

>>> from shapely.wkt import dumps, loads
>>> dumps(loads('POINT (0 0)'))
'POINT (0.0000000000000000 0.0000000000000000)'

Shapely can also integrate with other Python GIS packages using GeoJSON-like dicts.

>>> import json
>>> from shapely.geometry import mapping, shape
>>> s = shape(json.loads('{"type": "Point", "coordinates": [0.0, 0.0]}'))
>>> s
<shapely.geometry.point.Point object at 0x...>
>>> print(json.dumps(mapping(s)))
{"type": "Point", "coordinates": [0.0, 0.0]}

Development and Testing

Dependencies for developing Shapely are listed in requirements-dev.txt. Cython and Numpy are not required for production installations, only for development. Use of a virtual environment is strongly recommended.

$ virtualenv .
$ source bin/activate
(env)$ pip install -r requirements-dev.txt
(env)$ pip install -e .

We use py.test to run Shapely’s suite of unittests and doctests.

(env)$ python -m pytest

Support

Questions about using Shapely may be asked on the GIS StackExchange using the “shapely” tag.

Bugs may be reported at https://github.com/Toblerity/Shapely/issues.

Credits

Shapely is written by:

• Sean Gillies <[e-mail]>

• Oliver Tonnhofer <[e-mail]>

• Joshua Arnott <[e-mail]>

• Mike Toews <[e-mail]>

• Jacob Wasserman <[e-mail]>

• Aron Bierbaum <[e-mail]>

• Allan Adair <[e-mail]>

• Johannes Schönberger <[e-mail]>

• georgeouzou <[e-mail]>

• Phil Elson <[e-mail]>

• Howard Butler <[e-mail]>

• Kelsey Jordahl <[e-mail]>

• dokai <dokai@b426a367-1105-0410-b9ff-cdf4ab011145>

• Kevin Wurster <[e-mail]>

• Gabi Davar <[e-mail]>

• Thibault Deutsch <[e-mail]>

• Dave Collins <[e-mail]>

• fredj <[e-mail]>

• Brad Hards <[e-mail]>

• David Baumgold <[e-mail]>

• Henry Walshaw <[e-mail]>

• Jinkun Wang <[e-mail]>

• Marc Jansen <[e-mail]>

• Sampo Syrjanen <[e-mail]>

• Steve M. Kim <[e-mail]>

• Thomas Kluyver <[e-mail]>

• Morris Tweed <[e-mail]>

• Naveen Michaud-Agrawal <[e-mail]>

• Jeethu Rao <[e-mail]>

• Peter Sagerson <[e-mail]>

• Jason Sanford <[e-mail]>

• mindw <[e-mail]>

• Jamie Hall <[e-mail]>

• James Spencer <[e-mail]>

• Stephan Hügel <[e-mail]>

• Bas Couwenberg <[e-mail]>

• James Douglass <[e-mail]>

• Tobias Sauerwein <[e-mail]>

• WANG Aiyong <[e-mail]>

• Brandon Wood <[e-mail]>

• BertrandGervais <[e-mail]>

• Andy Freeland <[e-mail]>

• Benjamin Root <[e-mail]>

• giumas <[e-mail]>

• Leandro Lima <[e-mail]>

• Maarten Vermeyen <[e-mail]>

• joelostblom <[e-mail]>

• Marco De Nadai <[e-mail]>

• Johan Euphrosine <[e-mail]>

See also: https://github.com/Toblerity/Shapely/graphs/contributors.

Additional help from:

• Justin Bronn (GeoDjango) for ctypes inspiration

• Martin Davis (JTS)

• Sandro Santilli, Mateusz Loskot, Paul Ramsey, et al (GEOS Project)

Major portions of this work were supported by a grant (for Pleiades) from the U.S. National Endowment for the Humanities (http://www.neh.gov).

Changes

1.6.3 (2017-12-09)

• AttributeError is no longer raised when accessing __geo_interface__ of an empty polygon (#450).

• asShape now handles empty coordinates in mappings as shape does (#542). Please note that asShape is likely to be deprecated in a future version of Shapely.

• Check for length of LineString coordinates in speed mode, preventing crashes when using LineStrings with only one coordinate (#546).

1.6.2 (2017-10-30)

• A 1.6.2.post1 release has been made to fix a problem with macosx wheels uploaded to PyPI.

1.6.2 (2017-10-26)

• Handle a TypeError that can occur when geometries are torn down (#473, #528).

• Splitting a linestring by one of its end points will now succeed instead of failing with a ValueError (#524, #533).

• Missing documentation of a geometry’s overlaps predicate has been added (#522).

1.6.1 (2017-09-01)

• Avoid STRTree crashes due to dangling references (#505) by maintaining references to added geometries.

• Reduce log level to debug when reporting on calls to ctypes CDLL() that don’t succeed and are retried (#515).

• Clarification: applications like GeoPandas that need an empty geometry object should use BaseGeometry() instead of Point() or Polygon(). An EmptyGeometry class has been added in the master development branch and will be available in the next non-bugfix release.

1.6.0 (2017-08-21)

Shapely 1.6.0 adds new attributes to existing geometry classes and new functions (split() and polylabel()) to the shapely.ops module. Exceptions are consolidated in a shapely.errors module and logging practices have been improved. Shapely’s optional features depending on Numpy are now gathered into a requirements set named “vectorized” and these may be installed like pip install shapely[vectorized].

Much of the work on 1.6.0 was aimed to improve the project’s build and packaging scripts and to minimize run-time dependencies. Shapely now vendorizes packaging to use during builds only and never again invokes the geos-config utility at run-time.

In addition to the changes listed under the alpha and beta pre-releases below, the following change has been made to the project:

• Project documentation is now hosted at https://shapely.readthedocs.io/en/latest/.

Thank you all for using, promoting, and contributing to the Shapely project.

1.6b5 (2017-08-18)

Bug fixes:

• Passing a single coordinate to LineString() with speedups disabled now raises a ValueError as happens with speedups enabled. This resolves #509.

1.6b4 (2017-02-15)

Bug fixes:

• Isolate vendorized packaging in a _vendor directory, remove obsolete dist-info, and remove packaging from project requirements (resolves #468).

1.6b3 (2016-12-31)

Bug fixes:

• Level for log messages originating from the GEOS notice handler reduced from WARNING to INFO (#447).

• Permit speedups to be imported again without Numpy (#444).

1.6b2 (2016-12-12)

New features:

• Add support for GeometryCollection to shape and asShape functions (#422).

1.6b1 (2016-12-12)

Bug fixes:

• Implemented __array_interface__ for empty Points and LineStrings (#403).

1.6a3 (2016-12-01)

Bug fixes:

• Remove accidental hard requirement of Numpy (#431).

Packaging:

• Put Numpy in an optional requirement set named “vectorized” (#431).

1.6a2 (2016-11-09)

Bug fixes:

• Shapely no longer configures logging in geos.py (#415).

Refactoring:

• Consolidation of exceptions in shapely.errors.

• UnsupportedGEOSVersionError is raised when GEOS < 3.3.0 (#407).

Packaging:

• Added new library search paths to assist Anaconda (#413).

• geos-config will now be bypassed when NO_GEOS_CONFIG env var is set. This allows configuration of Shapely builds on Linux systems that for whatever reasons do not include the geos-config program (#322).

1.6a1 (2016-09-14)

New features:

• A new error derived from NotImplementedError, with a more useful message, is raised when the GEOS backend doesn’t support a called method (#216).

• The project() method of LineString has been extended to LinearRing geometries (#286).

• A new minimum_rotated_rectangle attribute has been added to the base geometry class (#354).

• A new shapely.ops.polylabel() function has been added. It computes a point suited for labeling concave polygons (#395).

• A new shapely.ops.split() function has been added. It splits a geometry by another geometry of lesser dimension: polygon by line, line by point (#293, #371).

• Polygon.from_bounds() constructs a Polygon from bounding coordinates (#392).

• Support for testing with Numpy 1.4.1 has been added (#301).

• Support creating all kinds of empty geometries from empty lists of Python objects (#397, #404).

Refactoring:

• Switch from SingleSidedBuffer() to OffsetCurve() for GEOS >= 3.3 (#270).

• Cython speedups are now enabled by default (#252).

Packaging:

• Packaging 16.7, a setup dependency, is vendorized (#314).

• Infrastructure for building manylinux1 wheels has been added (#391).

• The system’s geos-config program is now only checked when setup.py is executed, never during normal use of the module (#244).

• Added new library search paths to assist PyInstaller (#382) and Windows (#343).

1.5.17 (2016-08-31)

• Bug fix: eliminate memory leak in geom_factory() (#408).

• Bug fix: remove mention of negative distances in parallel_offset and note that vertices of right hand offset lines are reversed (#284).

1.5.16 (2016-05-26)

• Bug fix: eliminate memory leak when unpickling geometry objects (#384, #385).

• Bug fix: prevent crashes when attempting to pickle a prepared geometry, raising PicklingError instead (#386).

• Packaging: extension modules in the OS X wheels uploaded to PyPI link only libgeos_c.dylib now (you can verify and compare to previous releases with otool -L shapely/vectorized/_vectorized.so).

1.5.15 (2016-03-29)

• Bug fix: use uintptr_t to store pointers instead of long in _geos.pxi, preventing an overflow error (#372, #373). Note that this bug fix was erroneously reported to have been made in 1.5.14, but was not.

1.5.14 (2016-03-27)

• Bug fix: use type() instead of isinstance() when evaluating geometry equality, preventing instances of base and derived classes from being mistaken for equals (#317).

• Bug fix: ensure that empty geometries are created when constructors have no args (#332, #333).

• Bug fix: support app “freezing” better on Windows by not relying on the __file__ attribute (#342, #377).

• Bug fix: ensure that empty polygons evaluate to be == (#355).

• Bug fix: filter out empty geometries that can cause segfaults when creating and loading STRtrees (#345, #348).

• Bug fix: no longer attempt to reuse GEOS DLLs already loaded by Rasterio or Fiona on OS X (#374, #375).

1.5.13 (2015-10-09)

• Restore setup and runtime discovery and loading of GEOS shared library to state at version 1.5.9 (#326).

• On OS X we try to reuse any GEOS shared library that may have been loaded via import of Fiona or Rasterio in order to avoid a bug involving the GEOS AbstractSTRtree (#324, #327).

1.5.12 (2015-08-27)

• Remove configuration of root logger from libgeos.py (#312).

• Skip test_fallbacks on Windows (#308).

• Call setlocale(locale.LC_ALL, “”) instead of resetlocale() on Windows when tearing down the locale test (#308).

• Fix for Sphinx warnings (#309).

• Addition of .cache, .idea, .pyd, .pdb to .gitignore (#310).

1.5.11 (2015-08-23)

• Remove packaging module requirement added in 1.5.10 (#305). Distutils can’t parse versions using ‘rc’, but if we stick to ‘a’ and ‘b’ we will be fine.

1.5.10 (2015-08-22)

• Monkey patch affinity module by absolute reference (#299).

• Raise TopologicalError in relate() instead of crashing (#294, #295, #303).

1.5.9 (2015-05-27)

• Fix for 64 bit speedups compatibility (#274).

1.5.8 (2015-04-29)

• Setup file encoding bug fix (#254).

• Support for pyinstaller (#261).

• Major prepared geometry operation fix for Windows (#268, #269).

• Major fix for OS X binary wheel (#262).

1.5.7 (2015-03-16)

• Test and fix buggy error and notice handlers (#249).

1.5.6 (2015-02-02)

• Fix setup regression (#232, #234).

• SVG representation improvements (#233, #237).

1.5.5 (2015-01-20)

• MANIFEST changes to restore _geox.pxi (#231).

1.5.4 (2015-01-19)

• Fixed OS X binary wheel library load path (#224).

1.5.3 (2015-01-12)

• Fixed ownership and potential memory leak in polygonize (#223).

• Wider release of binary wheels for OS X.

1.5.2 (2015-01-04)

• Fail installation if GEOS dependency is not met, preventing update breakage (#218, #219).

1.5.1 (2014-12-04)

• Restore geometry hashing (#209).

1.5.0 (2014-12-02)

• Affine transformation speedups (#197).

• New == rich comparison (#195).

• Geometry collection constructor (#200).

• ops.snap() backed by GEOSSnap (#201).

• Clearer exceptions in cases of topological invalidity (#203).

1.4.4 (2014-11-02)

• Proper conversion of numpy float32 vals to coords (#186).

1.4.3 (2014-10-01)

• Fix for endianness bug in WKB writer (#174).

1.4.2 (2014-09-29)

• Fix bungled 1.4.1 release (#176).

1.4.1 (2014-09-23)

• Return of support for GEOS 3.2 (#176, #178).

1.4.0 (2014-09-08)

• SVG representations for IPython’s inline image protocol.

• Efficient and fast vectorized contains().

• Change mitre_limit default to 5.0; raise ValueError with 0.0 (#139).

• Allow mix of tuples and Points in sped-up LineString ctor (#152).

• New STRtree class (#73).

• Add ops.nearest_points() (#147).

• Faster creation of geometric objects from others (cloning) (#165).

• Removal of tests from package.

1.3.3 (2014-07-23)

• Allow single-part geometries as argument to ops.cacaded_union() (#135).

• Support affine transformations of LinearRings (#112).

1.3.2 (2014-05-13)

• Let LineString() take a sequence of Points (#130).

1.3.1 (2014-04-22)

• More reliable proxy cleanup on exit (#106).

• More robust DLL loading on all platforms (#114).

1.3.0 (2013-12-31)

• Include support for Python 3.2 and 3.3 (#56), minimum version is now 2.6.

• Switch to GEOS WKT/WKB Reader/Writer API, with defaults changed to enable 3D output dimensions, and to ‘trim’ WKT output for GEOS >=3.3.0.

• Use GEOS version instead of GEOS C API version to determine library capabilities (#65).

1.2.19 (2013-12-30)

• Add buffering style options (#55).

1.2.18 (2013-07-23)

• Add shapely.ops.transform.

• Permit empty sequences in collection constructors (#49, #50).

• Individual polygons in MultiPolygon.__geo_interface__ are changed to tuples to match Polygon.__geo_interface__ (#51).

• Add shapely.ops.polygonize_full (#57).

1.2.17 (2013-01-27)

• Avoid circular import between wkt/wkb and geometry.base by moving calls to GEOS serializers to the latter module.

• Set _ndim when unpickling (issue #6).

• Don’t install DLLs to Python’s DLL directory (#37).

• Add affinity module of affine transformation (#31).

• Fix NameError that blocked installation with PyPy (#40, #41).

1.2.16 (2012-09-18)

• Add ops.unary_union function.

• Alias ops.cascaded_union to ops.unary_union when GEOS CAPI >= (1,7,0).

• Add geos_version_string attribute to shapely.geos.

• Ensure parent is set when child geometry is accessed.

• Generate _speedups.c using Cython when building from repo when missing, stale, or the build target is “sdist”.

• The is_simple predicate of invalid, self-intersecting linear rings now returns False.

• Remove VERSION.txt from repo, it’s now written by the distutils setup script with value of shapely.__version__.

1.2.15 (2012-06-27)

• Eliminate numerical sensitivity in a method chaining test (Debian bug #663210).

• Account for cascaded union of random buffered test points being a polygon or multipolygon (Debian bug #666655).

• Use Cython to build speedups if it is installed.

• Avoid stumbling over SVN revision numbers in GEOS C API version strings.

1.2.14 (2012-01-23)

• A geometry’s coords property is now sliceable, yielding a list of coordinate values.

• Homogeneous collections are now sliceable, yielding a new collection of the same type.

1.2.13 (2011-09-16)

• Fixed errors in speedups on 32bit systems when GEOS references memory above 2GB.

• Add shapely.__version__ attribute.

• Update the manual.

1.2.12 (2011-08-15)

• Build Windows distributions with VC7 or VC9 as appropriate.

• More verbose report on failure to speed up.

• Fix for prepared geometries broken in 1.2.11.

• DO NOT INSTALL 1.2.11

1.2.11 (2011-08-04)

• Ignore AttributeError during exit.

• PyPy 1.5 support.

• Prevent operation on prepared geometry crasher (#12).

• Optional Cython speedups for Windows.

• Linux 3 platform support.

1.2.10 (2011-05-09)

• Add optional Cython speedups.

• Add is_cww predicate to LinearRing.

• Add function that forces orientation of Polygons.

• Disable build of speedups on Windows pending packaging work.

1.2.9 (2011-03-31)

• Remove extra glob import.

• Move examples to shapely.examples.

• Add box() constructor for rectangular polygons.

• Fix extraneous imports.

1.2.8 (2011-12-03)

• New parallel_offset method (#6).

• Support for Python 2.4.

1.2.7 (2010-11-05)

• Support for Windows eggs.

1.2.6 (2010-10-21)

• The geoms property of an empty collection yields [] instead of a ValueError (#3).

• The coords and geometry type sproperties have the same behavior as above.

• Ensure that z values carry through into products of operations (#4).

1.2.5 (2010-09-19)

• Stop distributing docs/_build.

• Include library fallbacks in test_dlls.py for linux platform.

1.2.4 (2010-09-09)

• Raise AttributeError when there’s no backend support for a method.

• Raise OSError if libgeos_c.so (or variants) can’t be found and loaded.

• Add geos_c DLL loading support for linux platforms where find_library doesn’t work.

1.2.3 (2010-08-17)

• Add mapping function.

• Fix problem with GEOSisValidReason symbol for GEOS < 3.1.

1.2.2 (2010-07-23)

• Add representative_point method.

1.2.1 (2010-06-23)

• Fixed bounds of singular polygons.

• Added shapely.validation.explain_validity function (#226).

1.2 (2010-05-27)

• Final release.

1.2rc2 (2010-05-26)

• Add examples and tests to MANIFEST.in.

• Release candidate 2.

1.2rc1 (2010-05-25)

• Release candidate.

1.2b7 (2010-04-22)

• Memory leak associated with new empty geometry state fixed.

1.2b6 (2010-04-13)

• Broken GeometryCollection fixed.

1.2b5 (2010-04-09)

• Objects can be constructed from others of the same type, thereby making copies. Collections can be constructed from sequences of objects, also making copies.

• Collections are now iterators over their component objects.

• New code for manual figures, using the descartes package.

1.2b4 (2010-03-19)

• Adds support for the “sunos5” platform.

1.2b3 (2010-02-28)

• Only provide simplification implementations for GEOS C API >= 1.5.

1.2b2 (2010-02-19)

• Fix cascaded_union bug introduced in 1.2b1 (#212).

1.2b1 (2010-02-18)

• Update the README. Remove cruft from setup.py. Add some version 1.2 metadata regarding required Python version (>=2.5,<3) and external dependency (libgeos_c >= 3.1).

1.2a6 (2010-02-09)

• Add accessor for separate arrays of X and Y values (#210).

TODO: fill gap here

1.2a1 (2010-01-20)

• Proper prototyping of WKB writer, and avoidance of errors on 64-bit systems (#191).

• Prototype libgeos_c functions in a way that lets py2exe apps import shapely (#189).

1.2 Branched (2009-09-19)

1.0.12 (2009-04-09)

• Fix for references held by topology and predicate descriptors.

1.0.11 (2008-11-20)

• Work around bug in GEOS 2.2.3, GEOSCoordSeq_getOrdinate not exported properly (#178).

1.0.10 (2008-11-17)

• Fixed compatibility with GEOS 2.2.3 that was broken in 1.0.8 release (#176).

1.0.9 (2008-11-16)

• Find and load MacPorts libgeos.

1.0.8 (2008-11-01)

• Fill out GEOS function result and argument types to prevent faults on a 64-bit arch.

1.0.7 (2008-08-22)

• Polygon rings now have the same dimensions as parent (#168).

• Eliminated reference cycles in polygons (#169).

1.0.6 (2008-07-10)

• Fixed adaptation of multi polygon data.

• Raise exceptions earlier from binary predicates.

• Beginning distributing new windows DLLs (#166).

1.0.5 (2008-05-20)

• Added access to GEOS polygonizer function.

• Raise exception when insufficient coordinate tuples are passed to LinearRing constructor (#164).

1.0.4 (2008-05-01)

• Disentangle Python and topological equality (#163).

• Add shape(), a factory that copies coordinates from a geo interface provider. To be used instead of asShape() unless you really need to store coordinates outside shapely for efficient use in other code.

• Cache GEOS geometries in adapters (#163).

1.0.3 (2008-04-09)

• Do not release GIL when calling GEOS functions (#158).

• Prevent faults when chaining multiple GEOS operators (#159).

1.0.2 (2008-02-26)

• Fix loss of dimensionality in polygon rings (#155).

1.0.1 (2008-02-08)

• Allow chaining expressions involving coordinate sequences and geometry parts (#151).

• Protect against abnormal use of coordinate accessors (#152).

• Coordinate sequences now implement the numpy array protocol (#153).

1.0 (2008-01-18)

• Final release.

1.0 RC2 (2008-01-16)

• Added temporary solution for #149.

1.0 RC1 (2008-01-14)

• First release candidate