Modified the default_option_parser function to return a parser using a VerbatimHelpFo...

[dead/census-tools.git] / bin / find_avg_population_density

diff --git a/bin/find_avg_population_density b/bin/find_avg_population_density
index e58d1cac06349e3462eb3c1997d38a8633d86c6f..42ed3e5138c69a3319b083134b8fa041e9cbc5c3 100755 (executable)
--- a/bin/find_avg_population_density
+++ b/bin/find_avg_population_density
@@ -1,27 +1,78 @@
 #!/usr/bin/python
 
+"""
+Find the average population density of a set of GPS coordinates.
+"""
+
+import sys
+import os
+import site
+
 # Basically, add '../src' to our path.
-import sys, os, site
+# Needed for the imports that follow.
 site.addsitedir(os.path.dirname(os.path.abspath(sys.argv[0])) + '/../src')
 
-import ExitCodes, GPS, SummaryFile1
+import Census
+import CLI
+import Configuration.Defaults
+import ExitCodes
+import GPS
+import StringUtils
+
+
+"""
+Parse the command line options. There's some magic involved here;
+otherwise, optparse woule like nothing more than to interpret GPS
+coordinates such as '-78.000000' as options.
+"""
+for idx, value in enumerate(sys.argv):
+    # Please oh please don't rename this script to something which
+    # validates as a negative float.
+    if (StringUtils.is_negative_float(value)):
+        sys.argv.insert(idx, '--')
+        # We have to break here, otherwise the negative argument
+        # will get shifted down the list, and we'll hit it again
+        # in the next iteration of enumerate(). And then it'll
+        # get shifted down the list...
+        break
+    
+usage = '%prog [options] <longitude> <latitude>'
 
-# Find the average population density of a set of GPS coordinates
-# given a (SF1) geographic header file.
+parser = CLI.default_option_parser(usage)
 
-if (len(sys.argv) < 4):
-    print "Usage: %s <latitude> <longitude> <geo_file>" % sys.argv[0]
-    raise SystemExit(ExitCodes.NotEnoughArgs)
+# Use this module's docstring as the description.
+parser.description = __doc__
+
+parser.add_option('-s',
+                  '--srid',
+                  type="int",
+                  help="SRID of the input geometry. Defaults to %s." % Configuration.Defaults.SRID,
+                  default=Configuration.Defaults.SRID)
+
+(options, args) = parser.parse_args()
+
+if len(args) < 2:
+    print "\nERROR: You must supply a longitude and latitude.\n"
+    parser.print_help()
+    print '' # Print a newline
+    raise SystemExit(ExitCodes.NOT_ENOUGH_ARGS)
 
-# If we made it here, it's sort of safe to parse the arguments
-# and hope they're in order.
 
 coords = GPS.Coordinates()
-coords.latitude = float(sys.argv[1])
-coords.longitude = float(sys.argv[2])
-geo_file_path = sys.argv[3]
+coords.longitude = float(args[0])
+coords.latitude = float(args[1])
+
+cdb = Census.Database(options.host,
+                      options.database,
+                      options.username,
+                      options.srid)
 
-avg_density = SummaryFile1.FindAveragePopulationDensity(coords, geo_file_path)
+avg_density = cdb.find_average_population_density(coords)
 
-print str(avg_density)
+if (avg_density != None):
+    print str(avg_density)
+else:
+    print 'Error: No rows returned.'
+    print 'Did you pass (longitude, latitude) in the correct order?'
+    raise SystemExit(ExitCodes.NO_RESULTS)