r.mask converted to Python

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@33553 15284696-431f-4ddb-bdfa-cd5b030d7da7

scripts/r.mask/r.mask.py

@@ -0,0 +1,103 @@
+#!/usr/bin/env python
+#
+############################################################################
+#
+# MODULE:       r.mask
+# AUTHOR(S):	Michael Barton, Arizona State University
+#               Markus Neteler
+#               Converted to Python by Glynn Clements
+# PURPOSE:      Facilitates creation of raster MASK using r.reclass
+# COPYRIGHT:	(C) 2005, 2007, 2008 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.
+#
+#############################################################################
+
+#%Module
+#%  description: Create a MASK for limiting raster operation
+#%  keywords: raster, mask
+#%End
+#%option
+#% key: input
+#% type: string
+#% gisprompt: old,cell,raster
+#% description: Raster map to use as MASK
+#% required: no
+#%END
+#%option
+#% key: maskcats
+#% type: string
+#% description: Category values to use for MASK (format: 1 2 3 thru 7 *)
+#% answer: *
+#%END
+#%flag
+#% key: i
+#% description: Create inverse MASK from specified 'maskcats' list
+#%END
+#%flag
+#% key: r
+#% description: Remove existing MASK (overrides other options)
+#%END
+
+import sys
+import os
+import grass
+import atexit
+import subprocess
+
+def cleanup():
+    if tmp:
+	grass.run_command('g.remove', rast = tmp, quiet = True)
+
+def main():
+    input = options['input']
+    maskcats = options['maskcats']
+    remove = flags['r']
+    invert = flags['i']
+
+    if not remove and not input:
+	grass.fatal("Required parameter <input> not set")
+
+    mapset = grass.gisenv()['MAPSET']
+    exists = bool(grass.find_file('MASK', element = 'cell', mapset = mapset)['file'])
+
+    if remove:
+	if exists:
+	    grass.run_command('g.remove', rast = 'MASK')
+	    grass.message("Raster MASK removed")
+ 	else:
+	    grass.warning("No existing MASK to remove")
+    else:
+	owstr = 'GRASS_OVERWRITE'
+	overwrite = owstr in os.environ and os.environ[owstr] != '0'
+	if exists and not overwrite:
+	    grass.fatal("MASK already found in current mapset. Delete first or overwrite")
+
+	p = grass.start_command('r.reclass', input = input, output = 'MASK', overwrite = True,
+				stdin = subprocess.PIPE)
+	p.stdin.write("%s = 1" % maskcats)
+	p.stdin.close()
+	p.wait()
+
+	if invert:
+	    global tmp
+	    tmp = "r_mask_%d" % os.getpid()
+	    grass.run_command('g.rename', rast = ('MASK',tmp), quiet = True)
+	    grass.run_command('r.mapcalc', expr = "MASK=if(isnull(%s),1,null())" % tmp)
+	    grass.run_command('g.remove', rast = tmp, quiet = True)
+	    grass.message("Inverted MASK created.")
+	else:
+	    grass.message("MASK created.")
+
+        grass.message("All subsequent raster operations will be limited to MASK area" +
+		      "Removing or renaming raster file named MASK will" +
+		      "restore raster operations to normal")
+
+if __name__ == "__main__":
+    options, flags = grass.parser()
+    tmp = None
+    atexit.register(cleanup)
+    main()
+