shapely.contains_properly

contains_properly(a, b, **kwargs)

Returns True if geometry B is completely inside geometry A, with no common boundary points.

A contains B properly if B intersects the interior of A but not the boundary (or exterior). This means that a geometry A does not “contain properly” itself, which contrasts with the contains function, where common points on the boundary are allowed.

Note: this function will prepare the geometries under the hood if needed. You can prepare the geometries in advance to avoid repeated preparation when calling this function multiple times.

Parameters:

a, bGeometry or array_like

**kwargs

See NumPy ufunc docs for other keyword arguments.

See also

contains

contains which allows common boundary points

prepare

improve performance by preparing a (the first argument)

Examples

>>> from shapely import Polygon
>>> area1 = Polygon([(0, 0), (3, 0), (3, 3), (0, 3), (0, 0)])
>>> area2 = Polygon([(0, 0), (1, 0), (1, 1), (0, 1), (0, 0)])
>>> area3 = Polygon([(1, 1), (2, 1), (2, 2), (1, 2), (1, 1)])

area1 and area2 have a common border:

>>> contains(area1, area2)
True
>>> contains_properly(area1, area2)
False

area3 is completely inside area1 with no common border:

>>> contains(area1, area3)
True
>>> contains_properly(area1, area3)
True