shapely.polygonize

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shapely.polygonize#

polygonize(geometries, **kwargs)#

Create polygons formed from the linework of a set of Geometries.

Polygonizes an array of Geometries that contain linework which represents the edges of a planar graph. Any type of Geometry may be provided as input; only the constituent lines and rings will be used to create the output polygons.

Lines or rings that when combined do not completely close a polygon will result in an empty GeometryCollection. Duplicate segments are ignored.

This function returns the polygons within a GeometryCollection. Individual Polygons can be obtained using get_geometry to get a single polygon or get_parts to get an array of polygons. MultiPolygons can be constructed from the output using shapely.multipolygons(shapely.get_parts(shapely.polygonize(geometries))).

Parameters:
geometriesarray_like

An array of geometries.

axisint

Axis along which the geometries are polygonized. The default is to perform a reduction over the last dimension of the input array. A 1D array results in a scalar geometry.

**kwargs

See NumPy ufunc docs for other keyword arguments.

Returns:
GeometryCollection or array of GeometryCollections

See also

get_parts, get_geometry
polygonize_full
node

Examples

>>> import shapely
>>> from shapely import LineString
>>> lines = [
...     LineString([(0, 0), (1, 1)]),
...     LineString([(0, 0), (0, 1)]),
...     LineString([(0, 1), (1, 1)])
... ]
>>> shapely.polygonize(lines)
<GEOMETRYCOLLECTION (POLYGON ((1 1, 0 0, 0 1, 1 1)))>
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