libraries/pyshapelib/pytest.py

import shapelib, dbflib, shptree

#
#       The the shapefile module
#

print "--- testing shapelib ---"

def test_shpobject(obj):
    # The vertices method returns the shape as a list of lists of tuples.
    print "vertices:", obj.vertices()
    
    # The part_types method returns a tuple with the types of every part
    print "part_types:", obj.part_types()

    # The extents returns a tuple with two 4-element lists with the min.
    # and max. values of the vertices.
    print "extents:", obj.extents()

    # The type attribute is the type code (one of the SHPT* constants
    # defined in the shapelib module)
    print "type:", obj.type

    # The id attribute is the shape id
    print "id:", obj.id
    
    # the __repr__ method returns a string that can be eval()'ed to 
    # recreate the object.  This __repr__ is also used by __str__
    # and print
    print "obj:", obj
    print "reconstruction using __repr__:",
    obj_repr = repr(obj)
    obj_copy = eval(obj_repr)
    if repr(obj_copy) == obj_repr:
        print "ok"
    else:
        print "failed"
    

def make_shapefile(filename):
    print "\n* Creating a ShapeFile"
    
    # Create a shapefile with polygons
    outfile = shapelib.create(filename, shapelib.SHPT_POLYGON)

    # Create one very simple polygon and write it to the shapefile.  The
    # vertices should be given in clockwise order to comply with the
    # shapefile specification.
    print "\nA very simple polygon"
    obj = shapelib.SHPObject(shapelib.SHPT_POLYGON, 1,
                             [[(10, 10), (10, 20), (20, 20), (10, 10)]])
    test_shpobject(obj)
    outfile.write_object(-1, obj)

    # Create a polygon with a hole.  Note that according to the
    # shapefile specification, the vertices of the outer ring have to be
    # in clockwise order and the inner rings have to be in counter
    # clockwise order.
    #
    # There's an optional fourth parameter which when given must be a
    # list of part types, one for each part of the shape.  For polygons,
    # the part type is always shapelib.SHPP_RING, though.  The part
    # types are only relevant for SHPT_MULTIPATCH shapefiles.
    print "\nPolygon with a hole"
    obj = shapelib.SHPObject(shapelib.SHPT_POLYGON, 1,
                             [[(0, 0), (0, 40), (40, 40), (40, 0), (0, 0)],
                              [(10, 10), (20, 10), (20, 20), (10, 20),(10, 10)],
                              ])
    test_shpobject(obj)
    outfile.write_object(-1, obj)

    # close the file.
    outfile.close()

def read_shapefile(filename):
    print "\n* Reading a ShapeFile"
    
    # open the shapefile
    shp = shapelib.ShapeFile(filename)

    # the info method returns a tuple (num_shapes, type, min, max) where
    # num_shapes is the number of shapes, type is the type code (one of
    # the SHPT* constants defined in the shapelib module) and min and
    # max are 4-element lists with the min. and max. values of the
    # vertices.
    print "info:", shp.info()

    # the cobject method returns a PyCObject containing the shapelib
    # SHPHandle. This is useful for passing shapefile objects to
    # C-Python extensions.
    print "cobject:", shp.cobject()
    
    n = shp.info()[0]
    for i in range(n):
        obj = shp.read_object(i)
        print "\nread_object(%i):" % i
        test_shpobject(obj)

    print "\n* SHPTree:"
    
    # build a quad tree from the shapefile. The first argument must be
    # the return value of the shape file object's cobject method (this
    # is currently needed to access the shape file at the C-level). The
    # second argument is the dimension and the third the maximum depth.
    # 0 means to guess an appropriate depth
    tree = shptree.SHPTree(shp.cobject(), 2, 0)

    # Retrieve the ids for a region. Here we just use the extents of the
    # object previously read from the shapefile
    minima, maxima = obj.extents()
    print tree.find_shapes(minima[:2], maxima[:2])


make_shapefile("testfile")
read_shapefile("testfile")

#
#       Test the DBF file module.
#

print "\n\n--- testing dbflib ---"

def make_dbf(file):
    # create a new dbf file and add three fields.
    dbf = dbflib.create(file)
    dbf.add_field("NAME", dbflib.FTString, 20, 0)
    dbf.add_field("INT", dbflib.FTInteger, 10, 0)
    dbf.add_field("FLOAT", dbflib.FTDouble, 10, 4)

def add_dbf_records(file):
    # add some records to file
    dbf = dbflib.open(file, "r+b")
    # Records can be added as a dictionary...
    dbf.write_record(0, {'NAME': "Weatherwax", "INT":1, "FLOAT":3.1415926535})
    # ... or as a sequence
    dbf.write_record(1, ("Ogg", 2, -1000.1234))

def list_dbf(file):
    # print the contents of a dbf file to stdout
    dbf = dbflib.DBFFile(file)
    print "%d records, %d fields" % (dbf.record_count(), dbf.field_count())
    format = ""
    for i in range(dbf.field_count()):
        type, name, len, decc = dbf.field_info(i)
        if type == 0:
            format = format + " %%(%s)%ds" % (name, len)
        elif type == 1:
            format = format + " %%(%s)%dd" % (name, len)
        elif type == 2:
            format = format + " %%(%s)%dg" % (name, len)
    print format
    for i in range(dbf.record_count()):
        print format % dbf.read_record(i)


make_dbf("testfile")
add_dbf_records("testfile")
list_dbf("testfile")
1	jan	1611	import shapelib, dbflib, shptree
2
3			#
4			# The the shapefile module
5			#
6
7	bramz	2741	print "--- testing shapelib ---"
8
9			def test_shpobject(obj):
10			# The vertices method returns the shape as a list of lists of tuples.
11			print "vertices:", obj.vertices()
12
13			# The part_types method returns a tuple with the types of every part
14			print "part_types:", obj.part_types()
15
16			# The extents returns a tuple with two 4-element lists with the min.
17			# and max. values of the vertices.
18			print "extents:", obj.extents()
19
20			# The type attribute is the type code (one of the SHPT* constants
21			# defined in the shapelib module)
22			print "type:", obj.type
23
24			# The id attribute is the shape id
25			print "id:", obj.id
26
27			# the __repr__ method returns a string that can be eval()'ed to
28			# recreate the object. This __repr__ is also used by __str__
29			# and print
30			print "obj:", obj
31			print "reconstruction using __repr__:",
32			obj_repr = repr(obj)
33			obj_copy = eval(obj_repr)
34			if repr(obj_copy) == obj_repr:
35			print "ok"
36			else:
37			print "failed"
38
39
40
41	jan	1611	def make_shapefile(filename):
42	bramz	2741	print "\n* Creating a ShapeFile"
43
44	bh	2637	# Create a shapefile with polygons
45			outfile = shapelib.create(filename, shapelib.SHPT_POLYGON)
46
47			# Create one very simple polygon and write it to the shapefile. The
48			# vertices should be given in clockwise order to comply with the
49			# shapefile specification.
50	bramz	2741	print "\nA very simple polygon"
51	jan	1611	obj = shapelib.SHPObject(shapelib.SHPT_POLYGON, 1,
52	bh	2637	[[(10, 10), (10, 20), (20, 20), (10, 10)]])
53	bramz	2741	test_shpobject(obj)
54	jan	1611	outfile.write_object(-1, obj)
55
56	bh	2637	# Create a polygon with a hole. Note that according to the
57			# shapefile specification, the vertices of the outer ring have to be
58			# in clockwise order and the inner rings have to be in counter
59			# clockwise order.
60			#
61			# There's an optional fourth parameter which when given must be a
62			# list of part types, one for each part of the shape. For polygons,
63			# the part type is always shapelib.SHPP_RING, though. The part
64			# types are only relevant for SHPT_MULTIPATCH shapefiles.
65	bramz	2741	print "\nPolygon with a hole"
66	bh	2637	obj = shapelib.SHPObject(shapelib.SHPT_POLYGON, 1,
67			[[(0, 0), (0, 40), (40, 40), (40, 0), (0, 0)],
68			[(10, 10), (20, 10), (20, 20), (10, 20),(10, 10)],
69			])
70	bramz	2741	test_shpobject(obj)
71	bh	2637	outfile.write_object(-1, obj)
72
73			# close the file.
74			outfile.close()
75
76	jan	1611	def read_shapefile(filename):
77	bramz	2741	print "\n* Reading a ShapeFile"
78
79	jan	1611	# open the shapefile
80			shp = shapelib.ShapeFile(filename)
81
82			# the info method returns a tuple (num_shapes, type, min, max) where
83			# num_shapes is the number of shapes, type is the type code (one of
84			# the SHPT* constants defined in the shapelib module) and min and
85			# max are 4-element lists with the min. and max. values of the
86			# vertices.
87	bramz	2741	print "info:", shp.info()
88	jan	1611
89			# the cobject method returns a PyCObject containing the shapelib
90			# SHPHandle. This is useful for passing shapefile objects to
91			# C-Python extensions.
92	bramz	2741	print "cobject:", shp.cobject()
93
94			n = shp.info()[0]
95			for i in range(n):
96			obj = shp.read_object(i)
97			print "\nread_object(%i):" % i
98			test_shpobject(obj)
99	jan	1611
100	bramz	2741	print "\n* SHPTree:"
101
102	jan	1611	# build a quad tree from the shapefile. The first argument must be
103			# 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
105			# second argument is the dimension and the third the maximum depth.
106			# 0 means to guess an appropriate depth
107			tree = shptree.SHPTree(shp.cobject(), 2, 0)
108
109			# Retrieve the ids for a region. Here we just use the extents of the
110			# object previously read from the shapefile
111			minima, maxima = obj.extents()
112			print tree.find_shapes(minima[:2], maxima[:2])
113
114
115			make_shapefile("testfile")
116			read_shapefile("testfile")
117
118			#
119			# Test the DBF file module.
120			#
121
122	bramz	2741	print "\n\n--- testing dbflib ---"
123
124	jan	1611	def make_dbf(file):
125			# create a new dbf file and add three fields.
126			dbf = dbflib.create(file)
127			dbf.add_field("NAME", dbflib.FTString, 20, 0)
128			dbf.add_field("INT", dbflib.FTInteger, 10, 0)
129			dbf.add_field("FLOAT", dbflib.FTDouble, 10, 4)
130
131			def add_dbf_records(file):
132			# add some records to file
133			dbf = dbflib.open(file, "r+b")
134			# Records can be added as a dictionary...
135			dbf.write_record(0, {'NAME': "Weatherwax", "INT":1, "FLOAT":3.1415926535})
136			# ... or as a sequence
137			dbf.write_record(1, ("Ogg", 2, -1000.1234))
138
139			def list_dbf(file):
140			# print the contents of a dbf file to stdout
141			dbf = dbflib.DBFFile(file)
142			print "%d records, %d fields" % (dbf.record_count(), dbf.field_count())
143			format = ""
144			for i in range(dbf.field_count()):
145			type, name, len, decc = dbf.field_info(i)
146			if type == 0:
147			format = format + " %%(%s)%ds" % (name, len)
148			elif type == 1:
149			format = format + " %%(%s)%dd" % (name, len)
150			elif type == 2:
151			format = format + " %%(%s)%dg" % (name, len)
152			print format
153			for i in range(dbf.record_count()):
154			print format % dbf.read_record(i)
155
156
157			make_dbf("testfile")
158			add_dbf_records("testfile")
159			list_dbf("testfile")
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