[GRASS-user] Use of v.in.ascii in python with stdin

[Pietro]

Hi Johannes,

On Mon, Jun 17, 2013 at 1:24 PM, Johannes Radinger
<johannesradinger at gmail.com> wrote:
> I want to create a point via python at a specific location using the
> v.in.ascii command. How can I also specify the colum names or how can a
> header be used in combination with the standard input. As it is only one
> single point I don't want to create a txt file containing the header and the
> info. I tried following in GRASS7:

I think that some of your parameters are not correct...

{{{
from grass.pygrass.modules import Module

ASCII = """cat,X,Y,Name
1,635828.3,223067.0,pub
2,643553.4,220711.5,pizzeria"""

COLS = 'cat int, x double precision, y double precision, name varchar(10)'

vina = Module('v.in.ascii', input='-', output='pnt__v_in_ascii',
                        format='point', separator=',', skip=1, x=2, y=3, cat=1,
                        columns=COLS, stdin_=ASCII, overwrite=True,
finish_=True)
}}}

Mostly with the same parameters you can run grass.write_command.
But If you are looking for a tool to "play" and experiment I highly
suggest pygrass:

{{{
from grass.pygrass.vector import VectorTopo
from grass.pygrass.geometry import Point

new = VectorTopo('mynewvect')
COLS = [(u'cat',       'INTEGER PRIMARY KEY'),  (u'name',      'VAR CHAR')]
new.open('w', tab_cols=COLS)
new.write(Point(635828.3, 223067.0), ('pub', ))
new.write(Point(643553.4, 220711.5), ('restaurant', ))
new.close()

new.open('r')
new.cat(1).attrs['name']  # return: pub
new.close()
}}}

If you are interested please have a look of the ipython notebook:

https://github.com/zarch/workshop-pygrass

you have just to clone, and from a running session of grass enter in
the directory and launch:

> ipython notebook

to have a briefly introduction to the library.

Have fun!

Pietro