[GRASS-dev] how to do g.region n=n+(defined by user input option) in a python script?

[Glynn Clements]

Helmut Kudrnovsky wrote:

>    regext = options['region_extension']

> with 
>     current_region = grass.region()
> n = current_region["n"]
> s = current_region["s"]
> e = current_region["e"]
> w = current_region["w"]
> 
> it could be defined, but then it says
> 
> Traceback (most recent call last):
>   File "C:\Users\myricaria\AppData\Roaming\GRASS7\addons\scr
> ipts\v.habitat.dem.py", line 202, in <module>
>     sys.exit(main())
>   File "C:\Users\myricaria\AppData\Roaming\GRASS7\addons\scr
> ipts\v.habitat.dem.py", line 159, in main
>     grass.run_command('g.region', n = n+regext,
> TypeError: unsupported operand type(s) for +: 'float' and
> 'str'

"regext" will be a string; you need to use e.g.

	regext = float(regext)

before you can do arithmetic with it.

Also, unless the purpose of the script is to modify the region for
subsequent commands, either use use_temp_region() to localise any
changes to the script.

-- 
Glynn Clements <glynn at gclements.plus.com>