app/django/contrib/gis/utils/ogrinfo.py
author Lennard de Rijk <ljvderijk@gmail.com>
Wed, 09 Sep 2009 21:14:22 +0200
changeset 2895 cad75f6ba411
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Added the GHOP modules to the callback. The ENABLE_MODULE has been added to ensure that the current build does not suffer from any weird artefacts that might occur due to the presence of this module. Of course in time it will be removed. Thanks Madhusudan for getting us this far ^_^. Minor CSS and image patches should follow shortly.

"""
This module includes some utility functions for inspecting the layout
of a GDAL data source -- the functionality is analogous to the output
produced by the `ogrinfo` utility.
"""

from django.contrib.gis.gdal import DataSource
from django.contrib.gis.gdal.geometries import GEO_CLASSES

def ogrinfo(data_source, num_features=10):
    """
    Walks the available layers in the supplied `data_source`, displaying
    the fields for the first `num_features` features.
    """

    # Checking the parameters.
    if isinstance(data_source, str):
        data_source = DataSource(data_source)
    elif isinstance(data_source, DataSource):
        pass
    else:
        raise Exception, 'Data source parameter must be a string or a DataSource object.'

    for i, layer in enumerate(data_source):
        print "data source : %s" % data_source.name
        print "==== layer %s" % i
        print "  shape type: %s" % GEO_CLASSES[layer.geom_type.num].__name__
        print "  # features: %s" % len(layer)
        print "         srs: %s" % layer.srs
        extent_tup = layer.extent.tuple
        print "      extent: %s - %s" % (extent_tup[0:2], extent_tup[2:4])
        print "Displaying the first %s features ====" % num_features

        width = max(*map(len,layer.fields))
        fmt = " %%%ss: %%s" % width
        for j, feature in enumerate(layer[:num_features]):
            print "=== Feature %s" % j
            for fld_name in layer.fields:
                type_name = feature[fld_name].type_name
                output = fmt % (fld_name, type_name)
                val = feature.get(fld_name)
                if val:
                    if isinstance(val, str):
                        val_fmt = ' ("%s")'
                    else:
                        val_fmt = ' (%s)'
                    output += val_fmt % val
                else:
                    output += ' (None)'
                print output

# For backwards compatibility.
sample = ogrinfo