[GRASS-SVN] r65346 - grass/trunk/lib/python/script
svn_grass at osgeo.org
svn_grass at osgeo.org
Sun May 31 21:04:56 PDT 2015
Author: wenzeslaus
Date: 2015-05-31 21:04:56 -0700 (Sun, 31 May 2015)
New Revision: 65346
Modified:
grass/trunk/lib/python/script/setup.py
Log:
pythonlib: add example and addons to setup.init function
Motivation: http://grasswiki.osgeo.org/w/index.php?title=Working_with_GRASS_without_starting_it_explicitly&diff=next&oldid=20818
Adding also an example which is simplified but fully sufficient (and tested for extreme cases) version of the first example on the wiki page:
http://grasswiki.osgeo.org/w/index.php?title=Working_with_GRASS_without_starting_it_explicitly&oldid=21422
Documentation should be kept with API. There is a too many misteries related to this topic. More improvementes could be done with lib/init/grass.py functions generalized and moved to lib/python/script/setup.py (see TODOs in the code).
Modified: grass/trunk/lib/python/script/setup.py
===================================================================
--- grass/trunk/lib/python/script/setup.py 2015-06-01 02:19:04 UTC (rev 65345)
+++ grass/trunk/lib/python/script/setup.py 2015-06-01 04:04:56 UTC (rev 65346)
@@ -1,33 +1,106 @@
-"""!@package grass.script.setup
+"""Setup and initialization functions
- at brief GRASS Python scripting module (setup)
+Function can be used in Python scripts to setup a GRASS environment
+without starting an actual GRASS session.
-Setup functions to be used in Python scripts.
+Usage::
-Usage:
+ import os
+ import sys
+ import subprocess
- at code
-from grass.script import setup as grass
+ # 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")
-grass.init()
-...
- at endcode
+ # 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 = 'grass70'
+ if sys.platform.startswith('win'):
+ # MS Windows
+ grass7bin = r'C:\OSGeo4W\bin\grass70.bat'
+ # uncomment when using standalone WinGRASS installer
+ # grass7bin = r'C:\Program Files (x86)\GRASS GIS 7.0.0\grass70.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-7.0.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}:\n{error}"
+ .format(cmd=' '.join(startcmd), error=err))
+ gisbase = out.strip('\n\r')
+
+ # 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
+
+ # launch session
+ rcfile = gscript.setup.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
+
+ # delete the rcfile
+ os.remove(rcfile)
+
+
(C) 2010-2012 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>
+ at author Vaclav Petras <wenzeslaus gmail.com>
"""
+# 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
def write_gisrc(dbase, location, mapset):
- """Write the gisrc file and return the gisrc path."""
+ """Write the ``gisrc`` file and return its path."""
fd, gisrc = tmpfile.mkstemp()
os.write(fd, "GISDBASE: %s\n" % dbase)
os.write(fd, "LOCATION_NAME: %s\n" % location)
@@ -37,31 +110,66 @@
def init(gisbase, dbase='', location='demolocation', mapset='PERMANENT'):
- """!Initialize system variables to run scripts without starting
- GRASS explicitly.
+ """Initialize system variables to run GRASS modules
- User is resposible to delete gisrc file.
+ This function is for running GRASS GIS without starting it
+ explicitly. No GRASS modules shall be called before call of this
+ function but any module or user script can be called afterwards
+ as if it would be called in an actual GRASS session. 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).
- @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')
- @return path to gisrc file
+ To create a (fake) GRASS session a ``gisrc`` file is created.
+ Caller is resposible for deleting the ``gisrc`` file.
+
+ Basic usage::
+
+ # ... setup GISBASE and PYTHON path
+ grass.script as gscript
+ gisrc = gscript.setup.init("/usr/lib/grass64",
+ "/home/john/grassdata",
+ "nc_spm_08", "user1")
+ # ... use GRASS modules
+ os.remove(gisrc)
+
+ :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)
"""
+ # TODO: why we don't set 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 sys.platform.startswith('win'): # added for winGRASS
+ 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')
+
# define LD_LIBRARY_PATH
if '@LD_LIBRARY_PATH_VAR@' not in os.environ:
os.environ['@LD_LIBRARY_PATH_VAR@'] = ''
os.environ['@LD_LIBRARY_PATH_VAR@'] += os.pathsep + os.path.join(gisbase, 'lib')
-
+
os.environ['GIS_LOCK'] = str(os.getpid())
# Set PYTHONPATH to find GRASS Python modules
+ # TODO: isn't this useless? user already imported this somehow
path = os.getenv('PYTHONPATH')
etcpy = os.path.join(gisbase, 'etc', 'python')
if path:
@@ -70,6 +178,9 @@
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
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