52 lines
1.9 KiB
Python
52 lines
1.9 KiB
Python
"""
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This module includes some utility functions for inspecting the layout
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of a GDAL data source -- the functionality is analogous to the output
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produced by the `ogrinfo` utility.
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"""
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from django.contrib.gis.gdal import DataSource
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from django.contrib.gis.gdal.geometries import GEO_CLASSES
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def ogrinfo(data_source, num_features=10):
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"""
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Walk the available layers in the supplied `data_source`, displaying
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the fields for the first `num_features` features.
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"""
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# Checking the parameters.
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if isinstance(data_source, str):
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data_source = DataSource(data_source)
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elif isinstance(data_source, DataSource):
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pass
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else:
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raise Exception('Data source parameter must be a string or a DataSource object.')
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for i, layer in enumerate(data_source):
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print("data source : %s" % data_source.name)
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print("==== layer %s" % i)
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print(" shape type: %s" % GEO_CLASSES[layer.geom_type.num].__name__)
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print(" # features: %s" % len(layer))
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print(" srs: %s" % layer.srs)
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extent_tup = layer.extent.tuple
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print(" extent: %s - %s" % (extent_tup[0:2], extent_tup[2:4]))
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print("Displaying the first %s features ====" % num_features)
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width = max(*map(len, layer.fields))
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fmt = " %%%ss: %%s" % width
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for j, feature in enumerate(layer[:num_features]):
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print("=== Feature %s" % j)
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for fld_name in layer.fields:
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type_name = feature[fld_name].type_name
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output = fmt % (fld_name, type_name)
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val = feature.get(fld_name)
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if val:
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if isinstance(val, str):
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val_fmt = ' ("%s")'
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else:
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val_fmt = ' (%s)'
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output += val_fmt % val
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else:
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output += ' (None)'
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print(output)
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