parsewkt
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A WKT Parser generated with grako
The WKT Parser was gernerated using grako https://pypi.python.org/pypi/grako
The ebnf file is the translation of http://svn.osgeo.org/postgis/trunk/doc/bnf-wkt.txt
The bnf to ebnf conversion was guided by http://stackoverflow.com/questions/14922242/how-to-convert-bnf-to-ebnf
The generation of parse.py is as easy as: /path/to/grako Wkt.ebnf -o parse.py
parsewkt is continually tested with Travis CI
.. image:: https://api.travis-ci.org/cleder/parsewkt.png :target: https://travis-ci.org/cleder/parsewkt
.. image:: https://coveralls.io/repos/cleder/parsewkt/badge.png?branch=master :target: https://coveralls.io/r/cleder/parsewkt?branch=master
Implementation Status
Currently implemented is parsing from WKT to a geo_interface compliant dictionary for the following types:
- POINT
- LINESTRING
- POLYGON
- MULTIPOINT
- MULTILINESTRING
- MULTIPOLYGON
- GEOMETRYCOLLECTION
The parser can parse the following types but they are currently not translated into python objects:
- COMPOUNDCURVE
- CIRCULARSTRING
- CURVEPOLYGON
- MULTICURVE
- POLYHEDRALSURFACE
- TIN
- TRIANGLE
Rationale
The parser was written to have a clean and complete parser for WKT. Other WKT to python parsers use regular expression to do the same and are more or less complete. I wanted to have a reference implementation that could handle any kind of valid WKT that you throw at it. You can also use it as a reference if you want to write your own parser with grako.
Usage
>>> from parsewkt import from_wkt
>>> gc = """GEOMETRYCOLLECTION(
... POINT(99 98),
... LINESTRING(1 1, 3 3),
... POLYGON((0 0, 0 1, 1 1, 0 0)),
... POLYGON((0 0, 0 9, 9 9, 9 0, 0 0), (5 5, 5 6, 6 6, 5 5)),
... MULTIPOLYGON(((0 0, 0 9, 9 9, 9 0, 0 0), (5 5, 5 6, 6 6, 5 5)))
... )"""
>>> from_wkt(gc)
{'type': 'GeometryCollection', 'geometries': (
{'type': 'Point', 'coordinates': (99.0, 98.0)},
{'type': 'LineString', 'coordinates': ((1.0, 1.0), (3.0, 3.0))},
{'type': 'Polygon', 'coordinates': (((0.0, 0.0), (0.0, 1.0), (1.0, 1.0), (0.0, 0.0)),)},
{'type': 'Polygon', 'coordinates': (((0.0, 0.0), (0.0, 9.0), (9.0, 9.0), (9.0, 0.0), (0.0, 0.0)), ((5.0, 5.0), (5.0, 6.0), (6.0, 6.0), (5.0, 5.0)))},
{'type': 'MultiPolygon', 'coordinates': ((((0.0, 0.0), (0.0, 9.0), (9.0, 9.0), (9.0, 0.0), (0.0, 0.0)), ((5.0, 5.0), (5.0, 6.0), (6.0, 6.0), (5.0, 5.0))),)})}
>>> tri = """TRIANGLE((0 0 0,0 1 0,1 1 0,0 0 0))"""
>>> from_wkt(tri)
Traceback (most recent call last):
File "<console>", line 1, in <module>
File "/home/.../parsewkt/parsewkt/wkt.py", line 307, in from_wkt
raise NotImplementedError
NotImplementedError
License
parsewkt is Copyright (C) 2013 by Christian Ledermann
You may use the tool under the terms of the BSD_-style license described in the enclosed LICENSE.txt file.
.. BSD: http://en.wikipedia.org/wiki/BSD_licenses#2-clause_license.28.22Simplified_BSD_License.22_or_.22FreeBSD_License.22.29