I'm trying to use v.generalize in the GRASS GIS library within a python code in PyCharm on my Linux Ubuntu system to make a shapefile that originally was a raster look less "blocky" by simplifying its geometries.

I installed grass and grass.script via the terminal in PyCharm by running pip install grass and pip install grass.script. However, when I try to import grass.script into my code and run it, I get the error: "No module named grass.script."

How do I get grass to work within PyCharm? My code is below.

import glob
import os
import subprocess
import geopandas
import grass.script as grass

file_path = input('Enter file path to the folder containing your categorized tifs: ')
while not os.path.isdir(file_path):
    file_path = input("\nThe path you have entered does not exist. Please try again: ")

mask = input("Input shp to use as mask: ")
while not os.path.isfile(mask):
    mask = input("\nThe file you have entered does not exist. Please try again: ")

mask = geopandas.read_file(mask)

for f in glob.glob(file_path + "*.tif"):  
    out_file = f[:-4] + ".shp"
    in_file = os.path.join(file_path, f) 
    cmdline = ['gdal_polygonize.py', in_file, out_file]
    out_file = geopandas.read_file(out_file)
    clipped = geopandas.clip(out_file, mask)
    # clipped.to_file(f[:-4] + '_clipped.shp')
    generalized_out = (f[:-4] + "_generalized.shp")
    cmdline2 = grass.run_command('v.generalize', input=clipped, method='chaiken', threshold=0.1, output=generalized_out)


So I looked at the grass wiki page and it says I need to run the following code, but am not sure what to put for the location and mapset. Any ideas?

import os
import sys
import subprocess

# path to the GRASS GIS launch script
# MS Windows
grass7bin_win = r'C:\OSGeo4W\bin\grass78dev.bat'
# uncomment when using standalone WinGRASS installer
# grass7bin_win = r'C:\Program Files (x86)\GRASS GIS 7.8.0\grass78.bat'
# Linux
grass7bin_lin = 'grass78'
# Mac OS X
# this is TODO
grass7bin_mac = '/Applications/GRASS/GRASS-7.8.app/'

# add your path to grassdata (GRASS GIS database) directory
gisdb = os.path.join(os.path.expanduser("~"), "grassdata")
# the following path is the default path on MS Windows
# gisdb = os.path.join(os.path.expanduser("~"), "Documents/grassdata")

# specify (existing) location and mapset
location = "nc_spm_08"
mapset   = "user1"

########### SOFTWARE
if sys.platform.startswith('linux'):
    # we assume that the GRASS GIS start script is available and in the PATH
    # query GRASS 7 itself for its GISBASE
    grass7bin = grass7bin_lin
elif sys.platform.startswith('win'):
    grass7bin = grass7bin_win
    raise OSError('Platform not configured.')

# query GRASS 7 itself for its GISBASE
startcmd = [grass7bin, '--config', 'path']

p = subprocess.Popen(startcmd, shell=False,
                     stdout=subprocess.PIPE, stderr=subprocess.PIPE)
out, err = p.communicate()
if p.returncode != 0:
    print >>sys.stderr, "ERROR: Cannot find GRASS GIS 7 start script (%s)" % startcmd
gisbase = out.strip('\n\r')

# Set GISBASE environment variable
os.environ['GISBASE'] = gisbase
# the following not needed with trunk
os.environ['PATH'] += os.pathsep + os.path.join(gisbase, 'extrabin')
# add path to GRASS addons
home = os.path.expanduser("~")
os.environ['PATH'] += os.pathsep + os.path.join(home, '.grass7', 'addons', 'scripts')

# define GRASS-Python environment
gpydir = os.path.join(gisbase, "etc", "python")

########### DATA
# Set GISDBASE environment variable
os.environ['GISDBASE'] = gisdb
# import GRASS Python bindings (see also pygrass)
import grass.script as gscript
import grass.script.setup as gsetup
# launch session
            gisdb, location, mapset)
gscript.message('Current GRASS GIS 7 environment:')
print gscript.gisenv()
gscript.message('Available raster maps:')
for rast in gscript.list_strings(type = 'rast'):
    print rast
gscript.message('Available vector maps:')
for vect in gscript.list_strings(type = 'vect'):
    print vect

1 Answer 1


I think that it's no enough to install and import the GRASS python modules. You need to do the initialization of a GRASS session as described in this wiki page

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