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shapely.polygons

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shapely.polygons#

polygons(geometries, holes=None, indices=None, out=None, **kwargs)#

Create an array of polygons.

Parameters:
geometriesarray_like

An array of linearrings or coordinates (see linearrings). Unless indices are given (see description below), this include the outer shells only. The holes argument should be used to create polygons with holes.

holesarray_like, optional

An array of lists of linearrings that constitute holes for each shell. Not to be used in combination with indices.

indicesarray_like, optional

Indices into the target array where input geometries belong. If provided, the holes are expected to be present inside geometries; the first geometry for each index is the outer shell and all subsequent geometries in that index are the holes. Both geometries and indices should be 1D and have matching sizes. Indices should be in increasing order. Missing indices result in a ValueError unless out is provided, in which case the original value in out is kept.

outndarray, optional

An array (with dtype object) to output the geometries into.

**kwargs

See NumPy ufunc docs for other keyword arguments. Ignored if indices is provided.

Examples

Polygons are constructed from rings:

>>> ring_1 = linearrings([[0, 0], [0, 10], [10, 10], [10, 0]])
>>> ring_2 = linearrings([[2, 6], [2, 7], [3, 7], [3, 6]])
>>> polygons([ring_1, ring_2])[0]
<POLYGON ((0 0, 0 10, 10 10, 10 0, 0 0))>
>>> polygons([ring_1, ring_2])[1]
<POLYGON ((2 6, 2 7, 3 7, 3 6, 2 6))>

Or from coordinates directly:

>>> polygons([[0, 0], [0, 10], [10, 10], [10, 0]])
<POLYGON ((0 0, 0 10, 10 10, 10 0, 0 0))>

Adding holes can be done using the holes keyword argument:

>>> polygons(ring_1, holes=[ring_2])
<POLYGON ((0 0, 0 10, 10 10, 10 0, 0 0), (2 6, 2 7, 3 7, 3 6, 2 6))>

Or using the indices argument:

>>> polygons([ring_1, ring_2], indices=[0, 1])[0]
<POLYGON ((0 0, 0 10, 10 10, 10 0, 0 0))>
>>> polygons([ring_1, ring_2], indices=[0, 1])[1]
<POLYGON ((2 6, 2 7, 3 7, 3 6, 2 6))>
>>> polygons([ring_1, ring_2], indices=[0, 0])[0]
<POLYGON ((0 0, 0 10, 10 10, 10 0, 0 0), (2 6, 2 7, 3 7, 3 6, 2 6))>

Missing input values (None) are skipped and may result in an empty polygon:

>>> polygons(None)
<POLYGON EMPTY>
>>> polygons(ring_1, holes=[None])
<POLYGON ((0 0, 0 10, 10 10, 10 0, 0 0))>
>>> polygons([ring_1, None], indices=[0, 0])[0]
<POLYGON ((0 0, 0 10, 10 10, 10 0, 0 0))>
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