Implement expected interface for Feature.properties

[artem]

for f in ds.features_at_point(merc):

print f

<mapnik._mapnik.Feature object at 0xb7f163ac>

on that, I'd expect to be able to call:

for (k,v) in f.properties:

but I can't. Also, if I do:

f.propertiestype?

I get back a mapnik._mapnik.Value object, and not a native python object as I'd expect

Also, if I do

for prop in f.properties:

you have to call key() and value(), it'd be good if there were python attributes for them

Nick

[artem]

I added two to_python converters:

1. std::pair<std::string,mapnik::value> to boost::python::tuple
2. mapnik::value to native Python types e.g int,float and unicode str.

and modified map_indexing_suite2.

Example

from mapnik import *

ds = Datasource(type='postgis',host='localhost',user='artem', dbname='planet_osm', table='planet_osm_polygon')

pt = Coord(-35555.19,6662160.5)

print "querying at point " + str(pt)
for f in ds.features_at_point(pt):
    for k,v in f.properties:
        print " %s = %s " % ( k,v )