Converts Oracle SDO_GEOMETRY into spatial objects which implements the __geo_interface__ protocol (GeoJSON-like dict). Supports also WKT conversion.
Project description
Library for converting Oracle SDO GEOMETRY into spatial objects which implements the __geo_interface__ protocol (GeoJSON-like dict).
Supported geometry types are : Point, Linestring, Polygon, MultiPoint, MultiLinestring, MultiPolygon and Collection.
Converted geometry can be used directly by other packages that support __geo_interface__ like Shapely or GeoPandas.
Kamutils also provides a WKT representation (Well Known Text) of the converted geometry.
Kamutils allows geometry conversion for database versions that does not implement SDO_UTIL
methods TO_WKTGEOMETRY
or TO_JSON
/ TO_GEOJSON
, or implement them partially.
For example, you may encounter an error 3D geometries are not supported by geometry WKB/WKT generation with the SDO_UTIL.TO_WKTGEOMETRY
method applied on geometry with X,Y,Z coordinates.
Kamutils includes other miscellaneous utilities.
License
Kamutils is licensed under CeCILL-B license, a BSD-like french/european license.
License in English : https://www.cecill.info/licences/Licence_CeCILL-B_V1-en.html
License in French : https://www.cecill.info/licences/Licence_CeCILL-B_V1-fr.html
Requirements
Kamutils has been tested with :
- Python 3.7
- oracledb 1.1.1
Dependencies : none
Oracle SDO GEOMETRY conversion
Example 1 - Read and convert geometry with convert_from_sdo_geometry()
import oracledb
from kamutils.spatial import convert_from_sdo_geometry
oracledb.init_oracle_client()
connection = oracledb.connect(user="Test", password="********",dsn="MY_DSN")
with connection.cursor() as cursor:
cursor.execute("select geometry, ID from MY_BASE.MY_TABLE where ID='l1'")
row = cursor.fetchone()
if row:
spatial_object = convert_from_sdo_geometry(row[0])
if spatial_object.error is None:
print('converted object :')
print(spatial_object)
print('srid :',spatial_object.srid)
print('error :',spatial_object.error)
print('to WKT:')
print(spatial_object.wkt())
else:
print(spatial_object.error)
print('id :',spatial_object.error.id)
print('msg :',spatial_object.error.msg)
output :
converted object :
<SpatialObject - type:LineString srid:None {'type': 'LineString', 'coordinates': [(10.0, 25.0, 0.0), (20.0, 30.0, 0.0), (25.0, 25.0, 0.0), (30.0, 30.0, 0.0)], 'measures': None}>
srid : None
error : None
to WKT:
LINESTRING Z(10.0 25.0 0.0,20.0 30.0 0.0,25.0 25.0 0.0,30.0 30.0 0.0)
output in case of error :
Error 2 : Unknown geometry : SDO_GTYPE = 0
id : 2
msg : Unknown geometry : SDO_GTYPE = 0
Example 2 - Interoperability
. . .
spo = convert_from_sdo_geometry(row[0])
import json
print('json dump :')
print(json.dumps(spo.__geo_interface__))
print()
from shapely import geometry
obj=geometry.shape(spo)
print('shapely :')
print(type(obj))
print(obj)
print()
import geojson
obj=geojson.mapping.to_mapping(spo)
print('geojson :')
print(type(obj))
print(obj)
print()
import plpygis
obj=plpygis.Geometry.shape(spo)
print('plpygis :')
print(type(obj))
print(obj)
output :
json dump :
{"type": "LineString", "coordinates": [[10.0, 25.0, 0.0], [20.0, 30.0, 0.0], [25.0, 25.0, 0.0], [30.0, 30.0, 0.0]]}
shapely :
<class 'shapely.geometry.linestring.LineString'>
LINESTRING Z (10 25 0, 20 30 0, 25 25 0, 30 30 0)
geojson :
<class 'dict'>
{'type': 'LineString', 'coordinates': [(10.0, 25.0, 0.0), (20.0, 30.0, 0.0), (25.0, 25.0, 0.0), (30.0, 30.0, 0.0)]}
plpygis :
<class 'plpygis.geometry.LineString'>
01020000800400000000000000000024400000000000003940000000000000000000000000000034400000000000003e4
000000000000000000000000000003940000000000000394000000000000000000000000000003e400000000000003e40
0000000000000000
Example 3 - Conversion to ArcGis geometry
import arcpy
. . .
spo = convert_from_sdo_geometry(row[0])
if spo.srid is None:
# supposing you know the actual coordinates system of the source geometry
srid = KNOWN_SRID
else:
srid = spo.srid
arcpy_geom = arcpy.FromWKT(spo.wkt(), arcpy.SpatialReference(srid))
Classes and fonctions
Function convert_from_sdo_geometry
: converts a SDO_GEOMETRY
object and returns a SpatialObject
instance.
Module : kamutils.spatial
Class SpatialObject
Module : kamutils.spatial
Properties :
type
: returns the geometry type (see Geometry types constants)srid
: returns the srid (Spatial Reference IDentifier) wich identifies the coordinate system of the geometry. If not defined, returnNone
error
: returns the conversion error if any orNone
.
error
is an instance of classError
__geo_interface__
: returns a GeoJSON dict representation of the geometry. The geometry is not converted to EPSG:4326 regardless of its srid.is_valid
: returnsTrue
if the geometry is valid, i.e. there is no conversion error,False
in other cases
Methods :
wkt()
: returns the WKT representation of the geometrygeometries()
: returns an iterator over all sub-objects in case of a collection (flattening all sub-collections). If theSpatialObject
is not a collection, the iterator returns the object itself.
Class Error
Module : kamutils.exceptions
Attributes :
id
: returns the error id (see Error codes)msg
: returns the error message
Geometry types
To import Geometry types constants :
from kamutils.spatial import GEOMETRY_TYPE
Constant list :
Constant name | Value |
---|---|
GEOMETRY_TYPE.POINT | 1 |
GEOMETRY_TYPE.LINESTRING | 2 |
GEOMETRY_TYPE.POLYGON | 3 |
GEOMETRY_TYPE.COLLECTION | 4 |
GEOMETRY_TYPE.MULTIPOINT | 5 |
GEOMETRY_TYPE.MULTILINESTRING | 6 |
GEOMETRY_TYPE.MULTIPOLYGON | 7 |
Error codes
To import Error codes constants :
from kamutils.exceptions import ERROR
Constant list :
Constant name | Value |
---|---|
ERROR.EXCEPTION | -1 |
ERROR.INVALID_SDO_GEOMETRY | 1 |
ERROR.UNKNOW_TYPE | 2 |
ERROR.UNSUPPORTED_GEOMETRY | 3 |
ERROR.INVALID_GEOMETRY | 4 |
Limitations
The following geometry types are partially supported :
SDO_ETYPE | SDO_INTERPRETATION | Type (*) | Limitation |
---|---|---|---|
1 | 0 | Oriented point | The point is converted but the orientation is ignored |
1 | > 1 | Point cluster | Converted to Multipoint |
2 | 2 | Line string made up of circular arcs | Circular arcs are transformed into straight line segments connecting the arc's coordinates |
4 | > 1 | Compound line string with vertices connected by straight line segments or by circular arcs | Circular arcs are transformed into straight line segments connecting the arc's coordinates |
1003 2003 |
2 | Polygon made up of a connected sequence of circular arcs | Circular arcs are transformed into straight line segments connecting the arc's coordinates |
1005 2005 |
Compound polygon with some vertices connected by straight line segments and some by circular arcs | Circular arcs are transformed into straight line segments connecting the arc's coordinates |
* From Oracle SDO_GEOMETRY Object Type - Values and Semantics in SDO_ELEM_INFO
The following geometry types are not supported by the current version. They produce an error UNSUPPORTED_GEOMETRY
.
SDO_ETYPE | SDO_INTERPRETATION | Type (*) |
---|---|---|
0 | Geometry types not supported by Oracle Spatial | |
2 | 3 | NURBS curve |
1003 | 3 | Optimized rectangle |
1003 | 4 | Circle |
1007 | 1 | Solid |
1007 | 3 | Solid of type 'optimized box' |
1008 | Multi Solid | |
2003 | 3 | Optimized rectangle |
2003 | 4 | Circle |
Other utilities
To be completed
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