PyWPS 4 is a restart of the PyWPS project to implement OGC WPS standards in Python. It has been started from scratch using Python 2.7 to allow future compatibility with Python 3. It aims to provide easier process definition through upper and lower level APIs and prepare for the next version of WPS standards. Development is occurring on GitHub with contributors including Jachym Cepicky, Alex Morega, and Jorge de Jesus.

1. PyWPS 4
Development restart
Jáchym ˇCepický1
1http://les-ejk.cz
Geoinformatics, Prague 2013

2. TOC
1 PyWPS
2 PyWPS 4

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

4. 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

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. Keywords

8. Keywords
rather bike, then a car

9. Keywords
#small

10. Keywords
#modular

11. Keywords
#fast

12. Keywords
#easy

13. Keywords
#slick

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

15. PyWPS 4
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

16. PyWPS 4
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

17. PyWPS 4
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

18. PyWPS 4
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

19. PyWPS 4
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

20. PyWPS 4
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

21. PyWPS 4
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

22. PyWPS 4
#geopython 2006

23. PyWPS 4
#geopython 2013

24. lxml http://lxml.org
GRASS-WPS, GRASS-Python
Werkzeug http://werkzeug.pocoo.org/
Python 3
Django
. . .

25. Process definition in PyWPS 3
class Buffer (WPSProcess ) :
def __init__ ( s e l f ) :
WPSProcess . __init__ ( self , i d e n t i f i e r =" buffe
s e l f . addComplexInput ( i d e n t i f i e r =" input " , . .
. . .
s e l f . addLiteralOutpu ( i d e n t i f i e r =" input " , . .
. . .
def execute ( s e l f ) :
. . .
return

26. Process definition in PyWPS 4 (proposal)
2-level APIs
Providing the low-level API (integration with GRASS,
writing a compatibility api for PyWPS-3, and defining a
bunch of processes programatically if the user needs that.
The process is just a callable
Inspired by Django
Upper-level API for easy user-written processes

27. PyWPS 4 - upper-level
class Buffer ( pywps . Process ) :
class Input :
distance = pywps . L i t e r a l ( value_type=pywps . F
layer = pywps . Complex ( a s _ f i l e =True , max_occ
class Output :
feature_count = pywps . L i t e r a l ( value_type=pyw
fortune = pywps . L i t e r a l ( value_type
def execute ( s e l f ) :
. . .

28. PyWPS 4 - low-level
def make_buffer ( request ) :
. . .
make_buffer_process = pywps . create_process (
i d e n t i f i e r = ’ makebuffer ’ , t i t l e = . . .
inputs =[
pywps . L i t e r a l ( i d e n t i f i e r = ’ distance ’ , value_
pywps . BoundingBox ( i d e n t i f i e r = ’ c l i p ’ ) ,
] ,
outputs =[
pywps . L i t e r a l ( i d e n t i f i e r = ’ feature_count ’ , v
pywps . L i t e r a l ( i d e n t i f i e r = ’ fortune ’ , value_ty
] ,
handler=make_buffer )
make_buffer_process ( )

29. Where, what, how, who?
http://github.org/jachym/pywps-4
Tests, Basic request parsing, process definition, . . .
Alex Morega @mgax, Jorge de Jesus, Jachym Cepicky
http://lists.osgeo.org/cgi-bin/mailman/
listinfo/pywps-dev

30. Where, what, how, who?
http://github.org/jachym/pywps-4
Tests, Basic request parsing, process definition, . . .
Alex Morega @mgax, Jorge de Jesus, Jachym Cepicky
http://lists.osgeo.org/cgi-bin/mailman/
listinfo/pywps-dev

31. Where, what, how, who?
http://github.org/jachym/pywps-4
Tests, Basic request parsing, process definition, . . .
Alex Morega @mgax, Jorge de Jesus, Jachym Cepicky
http://lists.osgeo.org/cgi-bin/mailman/
listinfo/pywps-dev

32. Where, what, how, who?
http://github.org/jachym/pywps-4
Tests, Basic request parsing, process definition, . . .
Alex Morega @mgax, Jorge de Jesus, Jachym Cepicky
http://lists.osgeo.org/cgi-bin/mailman/
listinfo/pywps-dev

33. thank you!
jachym@les-ejk.cz
http://github.org/jachym/pywps-4
questions?