"""Setup, initialization, and clean-up functions
Functions can be used in Python scripts to setup a GRASS environment
and session without using grassXY.
Usage::
import os
import sys
import subprocess
# define GRASS Database
# 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"
# path to the GRASS GIS launch script
# we assume that the GRASS GIS start script is available and on PATH
# query GRASS itself for its GISBASE
# (with fixes for specific platforms)
# needs to be edited by the user
grass7bin = 'grass78'
if sys.platform.startswith('win'):
# MS Windows
grass7bin = r'C:\OSGeo4W\bin\grass78.bat'
# uncomment when using standalone WinGRASS installer
# grass7bin = r'C:\Program Files (x86)\GRASS GIS 7.8.0\grass78.bat'
# this can be avoided if GRASS executable is added to PATH
elif sys.platform == 'darwin':
# Mac OS X
# TODO: this have to be checked, maybe unix way is good enough
grass7bin = '/Applications/GRASS/GRASS-7.8.app/'
# query GRASS GIS itself for its GISBASE
startcmd = [grass7bin, '--config', 'path']
try:
p = subprocess.Popen(startcmd, shell=False,
stdout=subprocess.PIPE, stderr=subprocess.PIPE)
out, err = p.communicate()
except OSError as error:
sys.exit("ERROR: Cannot find GRASS GIS start script"
" {cmd}: {error}".format(cmd=startcmd[0], error=error))
if p.returncode != 0:
sys.exit("ERROR: Issues running GRASS GIS start script"
" {cmd}: {error}"
.format(cmd=' '.join(startcmd), error=err))
gisbase = out.strip(os.linesep)
# set GISBASE environment variable
os.environ['GISBASE'] = gisbase
# define GRASS-Python environment
grass_pydir = os.path.join(gisbase, "etc", "python")
sys.path.append(grass_pydir)
# import (some) GRASS Python bindings
import grass.script as gscript
import grass.script.setup as gsetup
# launch session
rcfile = gsetup.init(gisbase, gisdb, location, mapset)
# example calls
gscript.message('Current GRASS GIS 7 environment:')
print gscript.gisenv()
gscript.message('Available raster maps:')
for rast in gscript.list_strings(type='raster'):
print rast
gscript.message('Available vector maps:')
for vect in gscript.list_strings(type='vector'):
print vect
# clean up at the end
gsetup.cleanup()
(C) 2010-2019 by the GRASS Development Team
This program is free software under the GNU General Public
License (>=v2). Read the file COPYING that comes with GRASS
for details.
@author Martin Landa <landa.martin gmail.com>
@author Vaclav Petras <wenzeslaus gmail.com>
@author Markus Metz
"""
# TODO: this should share code from lib/init/grass.py
# perhaps grass.py can import without much trouble once GISBASE
# is known, this would allow moving things from there, here
# then this could even do locking
import os
import sys
import tempfile as tmpfile
windows = sys.platform == 'win32'
[docs]def write_gisrc(dbase, location, mapset):
"""Write the ``gisrc`` file and return its path."""
gisrc = tmpfile.mktemp()
with open(gisrc, 'w') as rc:
rc.write("GISDBASE: %s\n" % dbase)
rc.write("LOCATION_NAME: %s\n" % location)
rc.write("MAPSET: %s\n" % mapset)
return gisrc
[docs]def set_gui_path():
"""Insert wxPython GRASS path to sys.path."""
gui_path = os.path.join(os.environ['GISBASE'], 'gui', 'wxpython')
if gui_path and gui_path not in sys.path:
sys.path.insert(0, gui_path)
[docs]def init(gisbase, dbase='', location='demolocation', mapset='PERMANENT'):
"""Initialize system variables to run GRASS modules
This function is for running GRASS GIS without starting it with the
standard script grassXY. No GRASS modules shall be called before
call of this function but any module or user script can be called
afterwards because a GRASS session has been set up. GRASS Python
libraries are usable as well in general but the ones using C
libraries through ``ctypes`` are not (which is caused by library
path not being updated for the current process which is a common
operating system limitation).
To create a GRASS session a ``gisrc`` file is created.
Caller is responsible for deleting the ``gisrc`` file.
Basic usage::
# ... setup GISBASE and PYTHON path before import
import grass.script as gscript
gisrc = gscript.setup.init("/usr/bin/grass7",
"/home/john/grassdata",
"nc_spm_08", "user1")
# ... use GRASS modules here
# end the session
gscript.setup.finish()
:param gisbase: path to GRASS installation
:param dbase: path to GRASS database (default: '')
:param location: location name (default: 'demolocation')
:param mapset: mapset within given location (default: 'PERMANENT')
:returns: path to ``gisrc`` file (to be deleted later)
"""
# Set GISBASE
os.environ['GISBASE'] = gisbase
mswin = sys.platform.startswith('win')
# define PATH
os.environ['PATH'] += os.pathsep + os.path.join(gisbase, 'bin')
os.environ['PATH'] += os.pathsep + os.path.join(gisbase, 'scripts')
if mswin: # added for winGRASS
os.environ['PATH'] += os.pathsep + os.path.join(gisbase, 'extrabin')
# add addons to the PATH
# copied and simplified from lib/init/grass.py
if mswin:
config_dirname = "GRASS7"
config_dir = os.path.join(os.getenv('APPDATA'), config_dirname)
else:
config_dirname = ".grass7"
config_dir = os.path.join(os.getenv('HOME'), config_dirname)
addon_base = os.path.join(config_dir, 'addons')
os.environ['GRASS_ADDON_BASE'] = addon_base
if not mswin:
os.environ['PATH'] += os.pathsep + os.path.join(addon_base, 'scripts')
os.environ['PATH'] += os.pathsep + os.path.join(addon_base, 'bin')
# define LD_LIBRARY_PATH
if 'LD_LIBRARY_PATH' not in os.environ:
os.environ['LD_LIBRARY_PATH'] = ''
os.environ['LD_LIBRARY_PATH'] += os.pathsep + os.path.join(gisbase, 'lib')
# TODO: lock the mapset?
os.environ['GIS_LOCK'] = str(os.getpid())
# Set GRASS_PYTHON and PYTHONPATH to find GRASS Python modules
if not os.getenv('GRASS_PYTHON'):
if sys.platform == 'win32':
os.environ['GRASS_PYTHON'] = "python3.exe"
else:
os.environ['GRASS_PYTHON'] = "python3"
path = os.getenv('PYTHONPATH')
etcpy = os.path.join(gisbase, 'etc', 'python')
if path:
path = etcpy + os.pathsep + path
else:
path = etcpy
os.environ['PYTHONPATH'] = path
# TODO: isn't this contra-productive? may fail soon since we cannot
# write to the installation (applies also to defaults for Location
# and mapset) I don't see what would be the use case here.
if not dbase:
dbase = gisbase
os.environ['GISRC'] = write_gisrc(dbase, location, mapset)
return os.environ['GISRC']
# clean-up functions when terminating a GRASS session
# these fns can only be called within a valid GRASS session
[docs]def clean_default_db():
# clean the default db if it is sqlite
from grass.script import db as gdb
from grass.script import core as gcore
conn = gdb.db_connection()
if conn and conn['driver'] == 'sqlite':
# check if db exists
gisenv = gcore.gisenv()
database = conn['database']
database = database.replace('$GISDBASE', gisenv['GISDBASE'])
database = database.replace('$LOCATION_NAME', gisenv['LOCATION_NAME'])
database = database.replace('$MAPSET', gisenv['MAPSET'])
if os.path.exists(database):
gcore.message(_("Cleaning up default sqlite database ..."))
gcore.start_command('db.execute', sql = 'VACUUM')
# give it some time to start
import time
time.sleep(0.1)
[docs]def call(cmd, **kwargs):
import subprocess
"""Wrapper for subprocess.call to deal with platform-specific issues"""
if windows:
kwargs['shell'] = True
return subprocess.call(cmd, **kwargs)
[docs]def clean_temp():
from grass.script import core as gcore
gcore.message(_("Cleaning up temporary files..."))
nul = open(os.devnull, 'w')
gisbase = os.environ['GISBASE']
call([os.path.join(gisbase, "etc", "clean_temp")], stdout=nul)
nul.close()
[docs]def finish():
"""Terminate the GRASS session and clean up
GRASS commands can no longer be used after this function has been
called
Basic usage::
import grass.script as gscript
gscript.setup.cleanup()
"""
clean_default_db()
clean_temp()
# TODO: unlock the mapset?
# unset the GISRC and delete the file
from grass.script import utils as gutils
gutils.try_remove(os.environ['GISRC'])
os.environ.pop('GISRC')
# remove gislock env var (not the gislock itself
os.environ.pop('GIS_LOCK')
