Shapely - Python Package - Polygons

Shapely - Python Package - Polygons

class Polygon(exterior[, interiors=None])
The Polygon constructor takes two positional parameters. The first is an ordered sequence of (x, y[, z]) point tuples and is treated exactly as in the LinearRing case. The second is an optional unordered sequence of ring-like sequences specifying the interior boundaries or “holes” of the feature.
Rings of a valid Polygon may not cross each other, but may touch at a single point only. Again, Shapely will not prevent the creation of invalid features, but exceptions will be raised when they are operated on.

Figure 1. On the left, a valid Polygon with one interior ring that touches the exterior ring at one point, and on the right a Polygon that is invalid because its interior ring touches the exterior ring at more than one point. The points that describe the rings are shown in grey.

Figure 2. On the left, a Polygon that is invalid because its exterior and interior rings touch along a line, and on the right, a Polygon that is invalid because its interior rings touch along a line.

A Polygon has non-zero area and non-zero length.
>>> from shapely.geometry import Polygon
>>> polygon = Polygon([(0, 0), (1, 1), (1, 0)])
>>> polygon.area
0.5
>>> polygon.length
3.4142135623730949

Its x-y bounding box is a (minx, miny, maxx, maxy) tuple.
>>> polygon.bounds
(0.0, 0.0, 1.0, 1.0)

strong@foreverstrong:~$ python
Python 2.7.12 (default, Dec  4 2017, 14:50:18) 
[GCC 5.4.0 20160609] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from shapely.geometry import Polygon
>>> polygon = Polygon([(0, 0), (1, 1), (1, 0)])
>>> polygon.area
0.5
>>> 
>>> polygon.length
3.414213562373095
>>> 
>>> polygon.bounds
(0.0, 0.0, 1.0, 1.0)
>>> 
>>> exit()
strong@foreverstrong:~$