[GRASS-user] SQL query in python scripts using v.to.rast

[Alessandro Sebastiani]

Hello to everybody ,
i* tried with this piece of code, following suggestios by both:*
# note that for the moment i reduced the street types to 3
>>>types = ("primary" , "secondary" , "tertiary")
>>>for typ in types:
>>>>    gscript.run_command ("v.to.rast" , input = "road_clip" , type =
"line" , where = "type=%s" % typ , output = ("r"+typ) , use = "attr" ,
attribute_column = "cat")

*nevertheless, i still get the following error message*
DBMI-SQLite driver error:
Error in sqlite3_prepare():
SELECT cat FROM road_clip WHERE type=primary
near "primary": syntax error
DBMI-SQLite errore del driver:
Error in sqlite3_prepare():
SELECT cat FROM road_clip WHERE type=primary
near "primary": syntax error
ERROR: Impossible to select recod from table <road_clip>
Traceback (most recent call last):
  File "/home/alessandro/Scrivania/script_grass/rast_quer_st
ats_exp.py", line 6, in <module>
    gscript.run_command ("v.to.rast" , input = "road_clip" ,
type = "line" , where = "type=%s" % typ , output = ("r"+typ)
, use = "attr" , attribute_column = "cat")
  File "/usr/lib/grass74/etc/python/grass/script/core.py",
line 421, in run_command
    return handle_errors(returncode, returncode, args,
kwargs)
  File "/usr/lib/grass74/etc/python/grass/script/core.py",
line 332, in handle_errors
    returncode=returncode)
grass.exceptions.CalledModuleError: L'esecuzione del modulo
None ['v.to.rast', 'use=attr', 'attribute_column=cat',
'type=line', 'input=road_clip', 'output=rprimary',
'where=type=primary'] è terminata con errori
Processo terminato con codice di return diverso da zero 1.


(Sun Nov 11 10:53:56 2018) Comando terminato (0 sec)

I read both error message and my piece of code time again and again, i was
not able to detect what i am doing wong!


Il giorno ven 9 nov 2018 alle ore 13:15 Micha Silver <tsvibar at gmail.com> ha
scritto:

> I would do as follows:
>
> (Notice that each street type will become a *separate* raster)
>
>
> On 11/9/18 1:49 PM, Alessandro Sebastiani wrote:
>
> Dear all
> i have a vector (downloaded from OpenStreetmap) with all the streets in my
> study area. Streets are divided in categories (there is a specific string
> column in the db). now i want to convert to raster each category
> separately. I now how to do that separately, but i was not able to automate
> that in a python script. here it is what i wrote:
> *>>>*import grass.script as gscript
> *>>>*types = ("primary" , "secondary" , "tertiary" , "service" ,
> "pedestrian" , "footway" , "residential" , "path")
> *>>>*for typ in types:
>
>     where_str = ("type = %s" % typ)
>
>     outrast = "_".join(["type", typ])
>
>     gscript.run_command("v.to.rast",
>
>             input = "road_clip", type = "line", where = where_str,
>
>             output = outrast, use="attr", attribute_column = "cat" )
>
> *>>>> *   gscript.run_command ("v.to.rast" , input = "road_clip" , type =
> "line" , where ="type"=typ , output = types, use = "attr" ,
> attribute_column = "cat").
> *I got the following traceback:*   File
> "/home/alessandro/GRASSDATA/5_citta_def/5_citt_def/.tmp
> /alessandro-Lenovo-G50-70/5500.6.py", line 6
>     gscript.run_command ("v.to.rast" , input = "road_clip" ,
> type = "line" , where ="type"=typ , output = types, use =
> "attr" , attribute_column = "cat")
>                               ^
> SyntaxError: invalid syntax
>
> i guess the syntax error is in the way i set the query, but i'm not sure.
> Thanks to everybody,
>
> _______________________________________________
> grass-user mailing listgrass-user at lists.osgeo.orghttps://lists.osgeo.org/mailman/listinfo/grass-user
>
> --
> Micha Silver
> Ben Gurion Univ.
> Sde Boker, Remote Sensing Lab
> cell: +972-523-665918
>
>
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