[GRASS-dev] python script problem...

[Massimiliano Cannata]

Hi all,
I'm new to python and I'm trying to build up a script...
My question is:
After I setted up an option of type double, How can I get it in a python 
variable?

h = float(os.getenv('GIS_OPT_h')) it doesn't work, it require a string 
or numeric attribute !?!?

how to do?

thanks,
Maxi
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Here is my script:
-----------------------
#!/usr/bin/python
# -*- coding:utf-8 -*-
import math

#%Module
#%  description: g.parser test script
#%  keywords: keyword1, keyword2
#%End
#%option
#%  key: h
#%  type: double
#%  description: Profondità del mare in prossimità della costa h
#%  required : yes
#%end
#%option
#%  key: ho
#%  type: double
#%  description: Profondità del mare in corrispondenza dell'epicentro
#%  required : yes
#%end
#%option
#%  key: Ho
#%  type: double
#%  description: Altezza d'onda nel punto di generazione dello tsunami
#%  required : yes
#%end

import sys
import os

def main():

#### add your code here ####
    print ""
    print "Value of GIS_OPT_h: %s" % os.getenv("GIS_OPT_h")
    print "Value of GIS_OPT_ho:  %s" % os.getenv("GIS_OPT_ho")
    print "Value of GIS_OPT_Ho:  %s" % os.getenv("GIS_OPT_Ho")

#### it works and print the user input ####

h = float(os.getenv('GIS_OPT_h'))
ho = os.getenv('GIS_OPT_ho')
Ho = os.getenv('GIS_OPT_Ho')

#### NOT WORKING ! i guess i need something similar to atof in C ANSI ####

Co=math.sqrt(9.8 * h)
print "celerità dell'onda=",Co

H= Ho * ((ho/h)**(0.25))
print "Altezza d'onda a riva=",H

U=Co * math.sqrt((1+H/h))
print "Velocità d'onda a riva=",U

L= 4 * 2.415 *h /(math.sqrt(3*H/h))
print "Lunghezza di un'onda solitaria=",L

k1=U**2 * L/(19.6)
print "k1=",k1

k2= U**2 * H/(39.2)
print "k2=",k2

#### end of your code ####
if __name__ == "__main__":
    if ( len(sys.argv) <= 1 or sys.argv[1] != "@ARGS_PARSED@" ):
        os.execvp("g.parser", [sys.argv[0]] + sys.argv)
    else:
    main();





-- 
-----------------------------------------------------
Dr. Massimiliano Cannata
Environmental & Geomatic Engineer

Institute of Earth Scences - SUPSI
Trevano, C.P. 72, CH-6952 Canobbio, SWITZERLAND

Tel:    +41 (0)58 / 666 62 14  
Fax:    +41 (0)58 / 666 62 09
E-mail: massimiliano.cannata at supsi.ch

Web: 
http://www.ist.supsi.ch
http://istgis.ist.supsi.ch:8001/geomatica/
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