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# The the shapefile module |
# The the shapefile module |
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# |
# |
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print "--- testing shapelib ---" |
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def test_shpobject(obj): |
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# The vertices method returns the shape as a list of lists of tuples. |
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print "vertices:", obj.vertices() |
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# The part_types method returns a tuple with the types of every part |
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print "part_types:", obj.part_types() |
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# The extents returns a tuple with two 4-element lists with the min. |
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# and max. values of the vertices. |
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print "extents:", obj.extents() |
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# The type attribute is the type code (one of the SHPT* constants |
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# defined in the shapelib module) |
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print "type:", obj.type |
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# The id attribute is the shape id |
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print "id:", obj.id |
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# the __repr__ method returns a string that can be eval()'ed to |
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# recreate the object. This __repr__ is also used by __str__ |
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# and print |
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print "obj:", obj |
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print "reconstruction using __repr__:", |
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obj_repr = repr(obj) |
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obj_copy = eval(obj_repr) |
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if repr(obj_copy) == obj_repr: |
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print "ok" |
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else: |
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print "failed" |
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def make_shapefile(filename): |
def make_shapefile(filename): |
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obj = shapelib.SHPObject(shapelib.SHPT_POLYGON, 1, |
print "\n* Creating a ShapeFile" |
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[[(10, 10), (20, 10), (20, 20), (10, 10)]]) |
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print obj.extents() |
# Create a shapefile with polygons |
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print obj.vertices() |
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outfile = shapelib.create(filename, shapelib.SHPT_POLYGON) |
outfile = shapelib.create(filename, shapelib.SHPT_POLYGON) |
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# Create one very simple polygon and write it to the shapefile. The |
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# vertices should be given in clockwise order to comply with the |
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# shapefile specification. |
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print "\nA very simple polygon" |
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obj = shapelib.SHPObject(shapelib.SHPT_POLYGON, 1, |
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[[(10, 10), (10, 20), (20, 20), (10, 10)]]) |
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test_shpobject(obj) |
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outfile.write_object(-1, obj) |
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# Create a polygon with a hole. Note that according to the |
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# shapefile specification, the vertices of the outer ring have to be |
| 58 |
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# in clockwise order and the inner rings have to be in counter |
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# clockwise order. |
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# |
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# There's an optional fourth parameter which when given must be a |
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# list of part types, one for each part of the shape. For polygons, |
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# the part type is always shapelib.SHPP_RING, though. The part |
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# types are only relevant for SHPT_MULTIPATCH shapefiles. |
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print "\nPolygon with a hole" |
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obj = shapelib.SHPObject(shapelib.SHPT_POLYGON, 1, |
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[[(0, 0), (0, 40), (40, 40), (40, 0), (0, 0)], |
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[(10, 10), (20, 10), (20, 20), (10, 20),(10, 10)], |
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]) |
| 70 |
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test_shpobject(obj) |
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outfile.write_object(-1, obj) |
outfile.write_object(-1, obj) |
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del outfile |
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# close the file. |
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outfile.close() |
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def read_shapefile(filename): |
def read_shapefile(filename): |
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print "\n* Reading a ShapeFile" |
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| 79 |
# open the shapefile |
# open the shapefile |
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shp = shapelib.ShapeFile(filename) |
shp = shapelib.ShapeFile(filename) |
| 81 |
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|
| 84 |
# the SHPT* constants defined in the shapelib module) and min and |
# the SHPT* constants defined in the shapelib module) and min and |
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# max are 4-element lists with the min. and max. values of the |
# max are 4-element lists with the min. and max. values of the |
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# vertices. |
# vertices. |
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print shp.info() |
print "info:", shp.info() |
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# read_object reads a shape |
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obj = shp.read_object(0) |
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# The vertices method returns the shape as a list of lists of tuples. |
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print obj.vertices()[0][:10] |
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# The extents returns a tuple with two 4-element lists with the min. |
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# and max. values of the vertices. |
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print obj.extents() |
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# The type attribute is the type code (one of the SHPT* constants |
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# defined in the shapelib module) |
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print obj.type |
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# The id attribute is the shape id |
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print obj.id |
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# the cobject method returns a PyCObject containing the shapelib |
# the cobject method returns a PyCObject containing the shapelib |
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# SHPHandle. This is useful for passing shapefile objects to |
# SHPHandle. This is useful for passing shapefile objects to |
| 91 |
# C-Python extensions. |
# C-Python extensions. |
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print shp.cobject() |
print "cobject:", shp.cobject() |
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| 94 |
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n = shp.info()[0] |
| 95 |
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for i in range(n): |
| 96 |
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obj = shp.read_object(i) |
| 97 |
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print "\nread_object(%i):" % i |
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test_shpobject(obj) |
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print "\n* SHPTree:" |
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# build a quad tree from the shapefile. The first argument must be |
# build a quad tree from the shapefile. The first argument must be |
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# the return value of the shape file object's cobject method (this |
# the return value of the shape file object's cobject method (this |
| 104 |
# is currently needed to access the shape file at the C-level). The |
# is currently needed to access the shape file at the C-level). The |
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# Test the DBF file module. |
# Test the DBF file module. |
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# |
# |
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print "\n\n--- testing dbflib ---" |
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def make_dbf(file): |
def make_dbf(file): |
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# create a new dbf file and add three fields. |
# create a new dbf file and add three fields. |
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dbf = dbflib.create(file) |
dbf = dbflib.create(file) |
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