1. PyWPS – Project status and demo
ˇ
´
Jachym Cepick´ 1
y
1 Geosense
s.r.o. http://geosense.cz
WPS Workshop

2. Jachym Cepicky
Forester
OpenSource GIS developer (former
user) - GRASS, OpenLayers, PyWPS,
...
Member of Board of directors of Open
Source Geospatial Foundation
(OSGeo.org)
@jachymc http://les-ejk.cz
http://www.openstreetmap.org/user/jachymc

3. TOC
1
About PyWPS
2
Code
3
PyWPS 4

4. What is PyWPS
OGC WPS on the Server
Since 2006
Python
http://pywps.wald.intevation.org
http://github.org/geopython/pywps

5. PyWPS - what it is NOT
PyWPS is no analytical tool or engine. It does not perform
any type of geospatial calculation.
PyWPS is not special XML parser or generator. It does not
validate your GMLs against given schemas (yet), it does
not build GML from Python objects.
It is not complicated

6. PyWPS - what it is NOT
PyWPS is no analytical tool or engine. It does not perform
any type of geospatial calculation.
PyWPS is not special XML parser or generator. It does not
validate your GMLs against given schemas (yet), it does
not build GML from Python objects.
It is not complicated

7. PyWPS - what it is NOT
PyWPS is no analytical tool or engine. It does not perform
any type of geospatial calculation.
PyWPS is not special XML parser or generator. It does not
validate your GMLs against given schemas (yet), it does
not build GML from Python objects.
It is not complicated

8. Keywords

9. Keywords
rather bike, then a car

10. Keywords
#small

11. Keywords
#modular

12. Keywords
#fast

13. Keywords
#easy

14. Keywords
#slick

15. Keywords
#accessories (GRASS, GDAL, Shapely, #python)

16. History of PyWPS
2006-11-10 version 1.0.0 Web User Interface for WPS
(Embrio).
2007-10-08 version 2.0.0 New version improved stability,
Process class, OpenLayers 2.x.
2008-11-06 version 3.0.0 New code structure, implementation
of WPS 1.0.0
2009-06-01 version 3.1.0 New generic JavaScript WPS Client
library and more.
2011-09-06 version 3.2.0 MapServer
2013 Moved to GitHub
http://github.com/geopython/pywps
2013-5 FOSS4G-CEE 2013, Bucharest, Started to work
on PyWPS-4

17. How does it work

18. How does it work
Internet, sharing

19. How does it work

20. How does it work

21. How does it work

22. How does it work
One process

23. How does it work
Two processes

24. How does it work
Process chain

25. TOC
1
About PyWPS
2
Code
3
PyWPS 4

26. Talk is cheap. Show me the code
1 from pywps.Process import WPSProcess
2 from osgeo import ogr
3 import types
4 [...]
5
WPSProcess.__init__(self,
6
identifier = "ogrbuffer", # must be same, as filename
7
title="Buffer process using OGR")
8 [...]
9
self.data = self.addComplexInput(identifier = "data")
10
self.size = self.addLiteralInput(identifier="size")
11
self.output =self.addComplexOutput(identifier="buffer")

27. Talk is cheap. Show me the code
1 from pywps.Process import WPSProcess
2 from osgeo import ogr
3 import types
4 [...]
5
WPSProcess.__init__(self,
6
identifier = "ogrbuffer", # must be same, as filename
7
title="Buffer process using OGR")
8 [...]
9
self.data = self.addComplexInput(identifier = "data")
10
self.size = self.addLiteralInput(identifier="size")
11
self.output =self.addComplexOutput(identifier="buffer")

28. Talk is cheap. Show me the code
1 from pywps.Process import WPSProcess
2 from osgeo import ogr
3 import types
4 [...]
5
WPSProcess.__init__(self,
6
identifier = "ogrbuffer", # must be same, as filename
7
title="Buffer process using OGR")
8 [...]
9
self.data = self.addComplexInput(identifier = "data")
10
self.size = self.addLiteralInput(identifier="size")
11
self.output =self.addComplexOutput(identifier="buffer")

29. Talk is cheap. Show me the code
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
def execute(self):
inSource = ogr.Open(self.data.getValue())
inLayer = inSource.GetLayer()
[...]
outLayer = outSource.CreateLayer(
out,None,ogr.wkbUnknown)
[...]
while index < featureCount:
self.status.set("Calculating buffer for feature %d from %d
(100*(index+1)/featureCount*1.0))
[...]
inGeometry = inFeature.GetGeometryRef()
# make the buffer
buff = inGeometry.Buffer(float(self.size.getValue()))
[...]
self.output.setValue(out)
return

30. Talk is cheap. Show me the code
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
def execute(self):
inSource = ogr.Open(self.data.getValue())
inLayer = inSource.GetLayer()
[...]
outLayer = outSource.CreateLayer(
out,None,ogr.wkbUnknown)
[...]
while index < featureCount:
self.status.set("Calculating buffer for feature %d from %d
(100*(index+1)/featureCount*1.0))
[...]
inGeometry = inFeature.GetGeometryRef()
# make the buffer
buff = inGeometry.Buffer(float(self.size.getValue()))
[...]
self.output.setValue(out)
return

31. What can be connected
Python* (GDAL/OGR, GRASS, MapServer, Shapely, Fiona, R, PostGIS, . . . )
Jython - Java* (GeoTools, JTS, GeoServer, . . . )
Any batch file

32. Tools, which are tested with PyWPS
¨
GRASS (GRASS-WPS interface, Soren Gebert)
R
Taverna (WPS-WSDL orchestration, Jorge de Jesus)
MapServer (output generation using OGC OWS, still concept)

33. TOC
1 About PyWPS
2 Code
3 PyWPS 4

34. Bright future
Started from scratch
Use Python 2.7 (for future 3.0 migration)
Try different interpreters of Python (pypy)
Easy parsing with lxml
Prepare for next WPS version
Change of the whole process concept

35. PyWPS 4
#geopython 2006

36. PyWPS 4
#geopython 2013

37. lxml http://lxml.org
GRASS-WPS, GRASS-Python
Werkzeug http://werkzeug.pocoo.org/
Python 3
Django
MapServer for output generation
Respect to new OGC WPS 2.0.0 features
...

38. Happy processing!
jachym.cepicky@gmail.com
http://les-ejk.cz
@jachymc
http://github.org/jachym/pywps-4
http://pywps.wald.intevation.org