from os.path import join, exists
import grass.lib.gis as libgis
libgis.G_gisinit("")
import grass.lib.vector as libvect
import ctypes
# import pygrass modules
from grass.pygrass.vector.vector_type import VTYPE
from grass.pygrass.errors import GrassError, must_be_open
from grass.pygrass.gis import Location
from grass.pygrass.vector.geometry import GEOOBJ as _GEOOBJ
from grass.pygrass.vector.geometry import read_line, read_next_line
from grass.pygrass.vector.geometry import Area as _Area
from grass.pygrass.vector.abstract import Info
from grass.pygrass.vector.basic import Bbox, Cats, Ilist
_NUMOF = {
"areas": libvect.Vect_get_num_areas,
"dblinks": libvect.Vect_get_num_dblinks,
"faces": libvect.Vect_get_num_faces,
"holes": libvect.Vect_get_num_holes,
"islands": libvect.Vect_get_num_islands,
"kernels": libvect.Vect_get_num_kernels,
"points": (libvect.Vect_get_num_primitives, libvect.GV_POINT),
"lines": (libvect.Vect_get_num_primitives, libvect.GV_LINE),
"centroids": (libvect.Vect_get_num_primitives, libvect.GV_CENTROID),
"boundaries": (libvect.Vect_get_num_primitives, libvect.GV_BOUNDARY),
"nodes": libvect.Vect_get_num_nodes,
"updated_lines": libvect.Vect_get_num_updated_lines,
"updated_nodes": libvect.Vect_get_num_updated_nodes,
"volumes": libvect.Vect_get_num_volumes,
}
# For test purposes
test_vector_name = "vector_doctest_map"
# =============================================
# VECTOR
# =============================================
[docs]class Vector(Info):
"""Vector class is the grass vector format without topology
>>> from grass.pygrass.vector import Vector
>>> test_vect = Vector(test_vector_name)
>>> test_vect.is_open()
False
>>> test_vect.mapset
''
>>> test_vect.exist()
True
>>> test_vect.overwrite
False
"""
def __init__(self, name, mapset="", *args, **kwargs):
# Set map name and mapset
super().__init__(name, mapset, *args, **kwargs)
self._topo_level = 1
self._class_name = "Vector"
self.overwrite = False
self._cats = []
def __repr__(self):
if self.exist():
return "%s(%r, %r)" % (self._class_name, self.name, self.mapset)
else:
return "%s(%r)" % (self._class_name, self.name)
def __iter__(self):
"""::
>>> test_vect = Vector(test_vector_name)
>>> test_vect.open(mode="r")
>>> features = [feature for feature in test_vect]
>>> features[:3]
[Point(10.000000, 6.000000), Point(12.000000, 6.000000), Point(14.000000, 6.000000)]
>>> test_vect.close()
..
""" # noqa: E501
# return (self.read(f_id) for f_id in xrange(self.num_of_features()))
return self
@must_be_open
def __next__(self):
"""::
>>> test_vect = Vector(test_vector_name)
>>> test_vect.open(mode="r")
>>> test_vect.next()
Point(10.000000, 6.000000)
>>> test_vect.next()
Point(12.000000, 6.000000)
>>> test_vect.close()
..
"""
return read_next_line(
self.c_mapinfo, self.table, self.writeable, is2D=not self.is_3D()
)
[docs] @must_be_open
def next(self):
return self.__next__()
[docs] @must_be_open
def rewind(self):
"""Rewind vector map to cause reads to start at beginning."""
if libvect.Vect_rewind(self.c_mapinfo) == -1:
raise GrassError("Vect_rewind raise an error.")
[docs] @must_be_open
def write(self, geo_obj, cat=None, attrs=None):
"""Write geometry features and attributes.
:param geo_obj: a geometry grass object define in
grass.pygrass.vector.geometry
:type geo_obj: geometry GRASS object
:param attrs: a list with the values that will be insert in the
attribute table.
:type attrs: list
:param cat: The category of the geometry feature, otherwise the
c_cats attribute of the geometry object will be used.
:type cat: integer
Open a new vector map ::
>>> new = VectorTopo("newvect")
>>> new.exist()
False
define the new columns of the attribute table ::
>>> cols = [("cat", "INTEGER PRIMARY KEY"), ("name", "TEXT")]
open the vector map in write mode
>>> new.open("w", tab_name="newvect", tab_cols=cols)
import a geometry feature ::
>>> from grass.pygrass.vector.geometry import Point
create two points ::
>>> point0 = Point(0, 0)
>>> point1 = Point(1, 1)
then write the two points on the map, with ::
>>> new.write(point0, cat=1, attrs=("pub",))
>>> new.write(point1, cat=2, attrs=("resturant",))
commit the db changes ::
>>> new.table.conn.commit()
>>> new.table.execute().fetchall()
[(1, 'pub'), (2, 'resturant')]
close the vector map ::
>>> new.close()
>>> new.exist()
True
then play with the map ::
>>> new.open(mode="r")
>>> new.read(1)
Point(0.000000, 0.000000)
>>> new.read(2)
Point(1.000000, 1.000000)
>>> new.read(1).attrs["name"]
'pub'
>>> new.read(2).attrs["name"]
'resturant'
>>> new.close()
>>> new.remove()
"""
self.n_lines += 1
if not isinstance(cat, int) and not isinstance(cat, str):
# likely the case of using 7.0 API
import warnings
warnings.warn(
"Vector.write(geo_obj, attrs=(...)) is"
" deprecated, specify cat explicitly",
DeprecationWarning,
)
# try to accommodate
attrs = cat
cat = None
if attrs and cat is None:
# TODO: this does not work as expected when there are
# already features in the map when we opened it
cat = (self._cats[-1] if self._cats else 0) + 1
if cat is not None and cat not in self._cats:
self._cats.append(cat)
if self.table is not None and attrs is not None:
attr = [
cat,
]
attr.extend(attrs)
cur = self.table.conn.cursor()
cur.execute(self.table.columns.insert_str, attr)
cur.close()
if cat is not None:
cats = Cats(geo_obj.c_cats)
cats.reset()
cats.set(cat, self.layer)
if geo_obj.gtype == _Area.gtype:
result = self._write_area(geo_obj)
result = libvect.Vect_write_line(
self.c_mapinfo, geo_obj.gtype, geo_obj.c_points, geo_obj.c_cats
)
if result == -1:
raise GrassError("Not able to write the vector feature.")
if self._topo_level == 2:
# return new feature id (on level 2)
geo_obj.id = result
else:
# return offset into file where the feature starts (on level 1)
geo_obj.offset = result
[docs] @must_be_open
def has_color_table(self):
"""Return if vector has color table associated in file system;
Color table stored in the vector's attribute table well be not checked
>>> test_vect = Vector(test_vector_name)
>>> test_vect.open(mode="r")
>>> test_vect.has_color_table()
False
>>> test_vect.close()
>>> from grass.pygrass.utils import copy, remove
>>> copy(test_vector_name, "mytest_vect", "vect")
>>> from grass.pygrass.modules.shortcuts import vector as v
>>> v.colors(map="mytest_vect", color="population", column="value")
Module('v.colors')
>>> mytest_vect = Vector("mytest_vect")
>>> mytest_vect.open(mode="r")
>>> mytest_vect.has_color_table()
True
>>> mytest_vect.close()
>>> remove("mytest_vect", "vect")
"""
loc = Location()
path = join(loc.path(), self.mapset, "vector", self.name, "colr")
return True if exists(path) else False
# =============================================
# VECTOR WITH TOPOLOGY
# =============================================
[docs]class VectorTopo(Vector):
"""Vector class with the support of the GRASS topology.
Open a vector map using the *with statement*: ::
>>> with VectorTopo(test_vector_name, mode="r") as test_vect:
... for feature in test_vect[:7]:
... print(feature.attrs["name"])
...
point
point
point
line
line
line
>>> test_vect.is_open()
False
..
"""
def __init__(self, name, mapset="", *args, **kwargs):
super().__init__(name, mapset, *args, **kwargs)
self._topo_level = 2
self._class_name = "VectorTopo"
def __len__(self):
return libvect.Vect_get_num_lines(self.c_mapinfo)
def __getitem__(self, key):
"""::
>>> test_vect = VectorTopo(test_vector_name)
>>> test_vect.open(mode="r")
>>> test_vect[:4]
[Point(10.000000, 6.000000), Point(12.000000, 6.000000), Point(14.000000, 6.000000)]
>>> test_vect.close()
..
""" # noqa: E501
if isinstance(key, slice):
return [
self.read(indx)
for indx in range(
key.start if key.start else 1,
key.stop if key.stop else len(self),
key.step if key.step else 1,
)
]
elif isinstance(key, int):
return self.read(key)
else:
raise ValueError("Invalid argument type: %r." % key)
[docs] @must_be_open
def num_primitive_of(self, primitive):
"""Return the number of primitive
:param primitive: the name of primitive to query; the supported values are:
* *boundary*,
* *centroid*,
* *face*,
* *kernel*,
* *line*,
* *point*
* *area*
* *volume*
:type primitive: str
::
>>> test_vect = VectorTopo(test_vector_name)
>>> test_vect.open(mode="r")
>>> test_vect.num_primitive_of("point")
3
>>> test_vect.num_primitive_of("line")
3
>>> test_vect.num_primitive_of("centroid")
4
>>> test_vect.num_primitive_of("boundary")
11
>>> test_vect.close()
..
"""
return libvect.Vect_get_num_primitives(self.c_mapinfo, VTYPE[primitive])
[docs] @must_be_open
def number_of(self, vtype):
"""Return the number of the chosen element type
:param vtype: the name of type to query; the supported values are:
*areas*, *dblinks*, *faces*, *holes*, *islands*,
*kernels*, *points*, *lines*, *centroids*, *boundaries*,
*nodes*, *line_points*, *update_lines*, *update_nodes*,
*volumes*
:type vtype: str
>>> test_vect = VectorTopo(test_vector_name)
>>> test_vect.open(mode="r")
>>> test_vect.number_of("areas")
4
>>> test_vect.number_of("islands")
2
>>> test_vect.number_of("holes")
0
>>> test_vect.number_of("lines")
3
>>> test_vect.number_of("nodes")
15
>>> test_vect.number_of("pizza")
... # doctest: +ELLIPSIS +NORMALIZE_WHITESPACE
Traceback (most recent call last):
...
ValueError: vtype not supported, use one of: 'areas', ...
>>> test_vect.close()
..
"""
if vtype in _NUMOF.keys():
if isinstance(_NUMOF[vtype], tuple):
fn, ptype = _NUMOF[vtype]
return fn(self.c_mapinfo, ptype)
else:
return _NUMOF[vtype](self.c_mapinfo)
else:
keys = "', '".join(sorted(_NUMOF.keys()))
raise ValueError("vtype not supported, use one of: '%s'" % keys)
[docs] @must_be_open
def num_primitives(self):
"""Return dictionary with the number of all primitives"""
output = {}
for prim in VTYPE.keys():
output[prim] = self.num_primitive_of(prim)
return output
[docs] @must_be_open
def viter(self, vtype, idonly=False):
"""Return an iterator of vector features
:param vtype: the name of type to query; the supported values are:
*areas*, *dblinks*, *faces*, *holes*, *islands*,
*kernels*, *line_points*, *lines*, *nodes*, *points*,
*update_lines*, *update_nodes*, *volumes*
:type vtype: str
:param idonly: variable to return only the id of features instead of
full features
:type idonly: bool
>>> test_vect = VectorTopo(test_vector_name, mode="r")
>>> test_vect.open(mode="r")
>>> areas = [area for area in test_vect.viter("areas")]
>>> areas[:3]
[Area(1), Area(2), Area(3)]
to sort the result in a efficient way, use: ::
>>> from operator import methodcaller as method
>>> areas.sort(key=method("area"), reverse=True) # sort the list
>>> for area in areas[:3]:
... print(area, area.area())
Area(1) 12.0
Area(2) 8.0
Area(4) 8.0
>>> areas = [area for area in test_vect.viter("areas")]
>>> for area in areas:
... print(area.centroid().cat)
...
3
3
3
3
>>> test_vect.close()
"""
is2D = not self.is_3D()
if vtype in _GEOOBJ.keys():
if _GEOOBJ[vtype] is not None:
ids = (indx for indx in range(1, self.number_of(vtype) + 1))
if idonly:
return ids
return (
_GEOOBJ[vtype](
v_id=indx,
c_mapinfo=self.c_mapinfo,
table=self.table,
writeable=self.writeable,
is2D=is2D,
)
for indx in ids
)
else:
keys = "', '".join(sorted(_GEOOBJ.keys()))
raise ValueError("vtype not supported, use one of: '%s'" % keys)
[docs] @must_be_open
def rewind(self):
"""Rewind vector map to cause reads to start at beginning. ::
>>> test_vect = VectorTopo(test_vector_name)
>>> test_vect.open(mode="r")
>>> test_vect.next()
Point(10.000000, 6.000000)
>>> test_vect.next()
Point(12.000000, 6.000000)
>>> test_vect.next()
Point(14.000000, 6.000000)
>>> test_vect.rewind()
>>> test_vect.next()
Point(10.000000, 6.000000)
>>> test_vect.close()
..
"""
libvect.Vect_rewind(self.c_mapinfo)
[docs] @must_be_open
def cat(self, cat_id, vtype, layer=None, generator=False, geo=None):
"""Return the geometry features with category == cat_id.
:param cat_id: the category number
:type cat_id: int
:param vtype: the type of geometry feature that we are looking for
:type vtype: str
:param layer: the layer number that will be used
:type layer: int
:param generator: if True return a generator otherwise it return a
list of features
:type generator: bool
"""
if geo is None and vtype not in _GEOOBJ:
keys = "', '".join(sorted(_GEOOBJ.keys()))
raise ValueError("vtype not supported, use one of: '%s'" % keys)
Obj = _GEOOBJ[vtype] if geo is None else geo
ilist = Ilist()
libvect.Vect_cidx_find_all(
self.c_mapinfo,
layer if layer else self.layer,
Obj.gtype,
cat_id,
ilist.c_ilist,
)
is2D = not self.is_3D()
if generator:
return (
read_line(
feature_id=v_id,
c_mapinfo=self.c_mapinfo,
table=self.table,
writeable=self.writeable,
is2D=is2D,
)
for v_id in ilist
)
else:
return [
read_line(
feature_id=v_id,
c_mapinfo=self.c_mapinfo,
table=self.table,
writeable=self.writeable,
is2D=is2D,
)
for v_id in ilist
]
[docs] @must_be_open
def read(self, feature_id):
"""Return a geometry object given the feature id.
:param int feature_id: the id of feature to obtain
>>> test_vect = VectorTopo(test_vector_name)
>>> test_vect.open(mode="r")
>>> feature1 = test_vect.read(0) # doctest: +ELLIPSIS
Traceback (most recent call last):
...
ValueError: The index must be >0, 0 given.
>>> feature1 = test_vect.read(5)
>>> feature1
Line([Point(12.000000, 4.000000), Point(12.000000, 2.000000), Point(12.000000, 0.000000)])
>>> feature1.length()
4.0
>>> test_vect.read(-1)
Centroid(7.500000, 3.500000)
>>> len(test_vect)
21
>>> test_vect.read(21)
Centroid(7.500000, 3.500000)
>>> test_vect.read(22) # doctest: +ELLIPSIS
Traceback (most recent call last):
...
IndexError: Index out of range
>>> test_vect.close()
""" # noqa: E501
return read_line(
feature_id,
self.c_mapinfo,
self.table,
self.writeable,
is2D=not self.is_3D(),
)
[docs] @must_be_open
def is_empty(self):
"""Return if a vector map is empty or not"""
primitives = self.num_primitives()
output = True
for v in primitives.values():
if v != 0:
output = False
break
return output
[docs] @must_be_open
def rewrite(self, geo_obj, cat, attrs=None, **kargs):
"""Rewrite a geometry features
>>> cols = [("cat", "INTEGER PRIMARY KEY"), ("name", "TEXT")]
Generate a new vector map
>>> test_vect = VectorTopo("newvect_2")
>>> test_vect.open("w", tab_name="newvect_2", tab_cols=cols, overwrite=True)
import a geometry feature ::
>>> from grass.pygrass.vector.geometry import Point
create two points ::
>>> point0 = Point(0, 0)
>>> point1 = Point(1, 1)
>>> point2 = Point(2, 2)
then write the two points on the map, with ::
>>> test_vect.write(point0, cat=1, attrs=("pub",))
>>> test_vect.write(point1, cat=2, attrs=("resturant",))
>>> test_vect.table.conn.commit() # save changes in the DB
>>> test_vect.table_to_dict()
{1: [1, 'pub'], 2: [2, 'resturant']}
>>> test_vect.close()
Now rewrite one point of the vector map: ::
>>> test_vect.open("rw")
>>> test_vect.rewrite(point2, cat=1, attrs=("Irish Pub",))
>>> test_vect.table.conn.commit() # save changes in the DB
>>> test_vect.close()
Check the output:
>>> test_vect.open("r")
>>> test_vect[1] == point2
True
>>> test_vect[1].attrs["name"] == "Irish Pub"
True
>>> test_vect.close()
>>> test_vect.remove()
"""
if self.table is not None and attrs:
self.table.update(key=cat, values=attrs)
elif self.table is None and attrs:
print(
"Table for vector {name} does not exist, attributes not"
" loaded".format(name=self.name)
)
libvect.Vect_cat_set(geo_obj.c_cats, self.layer, cat)
result = libvect.Vect_rewrite_line(
self.c_mapinfo, cat, geo_obj.gtype, geo_obj.c_points, geo_obj.c_cats
)
if result == -1:
raise GrassError("Not able to write the vector feature.")
# return offset into file where the feature starts
geo_obj.offset = result
[docs] @must_be_open
def delete(self, feature_id):
"""Remove a feature by its id
:param feature_id: the id of the feature
:type feature_id: int
"""
if libvect.Vect_rewrite_line(self.c_mapinfo, feature_id) == -1:
raise GrassError("C function: Vect_rewrite_line.")
[docs] @must_be_open
def restore(self, geo_obj):
if hasattr(geo_obj, "offset"):
if (
libvect.Vect_restore_line(self.c_mapinfo, geo_obj.offset, geo_obj.id)
== -1
):
raise GrassError("C function: Vect_restore_line.")
else:
raise ValueError("The value have not an offset attribute.")
[docs] @must_be_open
def bbox(self):
"""Return the BBox of the vecor map"""
bbox = Bbox()
if libvect.Vect_get_map_box(self.c_mapinfo, bbox.c_bbox) == 0:
raise GrassError("I can not find the Bbox.")
return bbox
[docs] def close(self, build=True, release=True):
"""Close the VectorTopo map, if release is True, the memory
occupied by spatial index is released"""
if release:
libvect.Vect_set_release_support(self.c_mapinfo)
super().close(build=build)
[docs] @must_be_open
def table_to_dict(self, where=None):
"""Return the attribute table as a dictionary with the category as keys
The columns have the order of the self.table.columns.names() list.
Examples
>>> from grass.pygrass.vector import VectorTopo
>>> from grass.pygrass.vector.basic import Bbox
>>> test_vect = VectorTopo(test_vector_name)
>>> test_vect.open("r")
>>> test_vect.table_to_dict()
{1: [1, 'point', 1.0], 2: [2, 'line', 2.0], 3: [3, 'centroid', 3.0]}
>>> test_vect.table_to_dict(where="value > 2")
{3: [3, 'centroid', 3.0]}
>>> test_vect.table_to_dict(where="value > 0")
{1: [1, 'point', 1.0], 2: [2, 'line', 2.0], 3: [3, 'centroid', 3.0]}
>>> test_vect.table.filters.get_sql()
'SELECT cat,name,value FROM vector_doctest_map WHERE value > 0 ORDER BY cat;'
"""
if self.table is not None:
table_dict = {}
# Get the category index
cat_index = self.table.columns.names().index("cat")
# Prepare a filter
if where is not None:
self.table.filters.where(where)
self.table.filters.order_by("cat")
self.table.filters.select(",".join(self.table.columns.names()))
# Execute the query and fetch the result
cur = self.table.execute()
entries = cur.fetchall()
# Generate the dictionary
for entry in entries:
table_dict[entry[cat_index]] = list(entry)
return table_dict
return None
[docs] @must_be_open
def features_to_wkb_list(self, bbox=None, feature_type="point", field=1):
"""Return all features of type point, line, boundary or centroid
as a list of Well Known Binary representations (WKB)
(id, cat, wkb) triplets located in a specific
bounding box.
:param bbox: The boundingbox to search for features,
if bbox=None the boundingbox of the whole
vector map layer is used
:type bbox: grass.pygrass.vector.basic.Bbox
:param feature_type: The type of feature that should be converted to
the Well Known Binary (WKB) format. Supported are:
'point' -> libvect.GV_POINT 1
'line' -> libvect.GV_LINE 2
'boundary' -> libvect.GV_BOUNDARY 3
'centroid' -> libvect.GV_CENTROID 4
:type type: string
:param field: The category field
:type field: integer
:return: A list of triplets, or None if nothing was found
The well known binary are stored in byte arrays.
Examples:
>>> from grass.pygrass.vector import VectorTopo
>>> from grass.pygrass.vector.basic import Bbox
>>> test_vect = VectorTopo(test_vector_name)
>>> test_vect.open("r")
>>> bbox = Bbox(north=20, south=-1, east=20, west=-1)
>>> result = test_vect.features_to_wkb_list(bbox=bbox, feature_type="point")
>>> len(result)
3
>>> for entry in result:
... f_id, cat, wkb = entry
... print((f_id, cat, len(wkb)))
...
(1, 1, 21)
(2, 1, 21)
(3, 1, 21)
>>> result = test_vect.features_to_wkb_list(bbox=None, feature_type="line")
>>> len(result)
3
>>> for entry in result:
... f_id, cat, wkb = entry
... print((f_id, cat, len(wkb)))
...
(4, 2, 57)
(5, 2, 57)
(6, 2, 57)
>>> result = test_vect.features_to_wkb_list(bbox=bbox, feature_type="boundary")
>>> len(result)
11
>>> result = test_vect.features_to_wkb_list(bbox=None, feature_type="centroid")
>>> len(result)
4
>>> for entry in result:
... f_id, cat, wkb = entry
... print((f_id, cat, len(wkb)))
...
(19, 3, 21)
(18, 3, 21)
(20, 3, 21)
(21, 3, 21)
>>> result = test_vect.features_to_wkb_list(bbox=bbox, feature_type="blub")
Traceback (most recent call last):
...
grass.exceptions.GrassError: Unsupported feature type <blub>, supported are <point,line,boundary,centroid>
>>> test_vect.close()
""" # noqa: E501
supported = ["point", "line", "boundary", "centroid"]
if feature_type.lower() not in supported:
raise GrassError(
"Unsupported feature type <%s>, "
"supported are <%s>" % (feature_type, ",".join(supported))
)
if bbox is None:
bbox = self.bbox()
bboxlist = self.find_by_bbox.geos(
bbox, type=feature_type.lower(), bboxlist_only=True
)
if bboxlist is not None and len(bboxlist) > 0:
wkb_list = []
line_p = libvect.line_pnts()
line_c = libvect.line_cats()
size = ctypes.c_size_t()
cat = ctypes.c_int()
error = ctypes.c_int()
for f_id in bboxlist.ids:
barray = libvect.Vect_read_line_to_wkb(
self.c_mapinfo,
ctypes.byref(line_p),
ctypes.byref(line_c),
f_id,
ctypes.byref(size),
ctypes.byref(error),
)
if not barray:
if error == -1:
raise GrassError(
_("Unable to read line of feature %i" % (f_id))
)
if error == -2:
print("Empty feature %i" % (f_id))
continue
ok = libvect.Vect_cat_get(
ctypes.byref(line_c), field, ctypes.byref(cat)
)
if ok < 1:
pcat = None
else:
pcat = cat.value
wkb_list.append((f_id, pcat, ctypes.string_at(barray, size.value)))
libgis.G_free(barray)
return wkb_list
return None
[docs] @must_be_open
def areas_to_wkb_list(self, bbox=None, field=1):
"""Return all features of type point, line, boundary or centroid
as a list of Well Known Binary representations (WKB)
(id, cat, wkb) triplets located in a specific
bounding box.
:param bbox: The boundingbox to search for features,
if bbox=None the boundingbox of the whole
vector map layer is used
:type bbox: grass.pygrass.vector.basic.Bbox
:param field: The centroid category field
:type field: integer
:return: A list of triplets, or None if nothing was found
The well known binary are stored in byte arrays.
Examples:
>>> from grass.pygrass.vector import VectorTopo
>>> from grass.pygrass.vector.basic import Bbox
>>> test_vect = VectorTopo(test_vector_name)
>>> test_vect.open("r")
>>> bbox = Bbox(north=20, south=-1, east=20, west=-1)
>>> result = test_vect.areas_to_wkb_list(bbox=bbox)
>>> len(result)
4
>>> for entry in result:
... a_id, cat, wkb = entry
... print((a_id, cat, len(wkb)))
...
(1, 3, 225)
(2, 3, 141)
(3, 3, 93)
(4, 3, 141)
>>> result = test_vect.areas_to_wkb_list()
>>> len(result)
4
>>> for entry in result:
... a_id, cat, wkb = entry
... print((a_id, cat, len(wkb)))
...
(1, 3, 225)
(2, 3, 141)
(3, 3, 93)
(4, 3, 141)
>>> test_vect.close()
"""
if bbox is None:
bbox = self.bbox()
bboxlist = self.find_by_bbox.areas(bbox, bboxlist_only=True)
if bboxlist is not None and len(bboxlist) > 0:
wkb_list = []
line_c = libvect.line_cats()
size = ctypes.c_size_t()
cat = ctypes.c_int()
for a_id in bboxlist.ids:
barray = libvect.Vect_read_area_to_wkb(
self.c_mapinfo, a_id, ctypes.byref(size)
)
if not barray:
raise GrassError(_("Unable to read area with id %i" % (a_id)))
pcat = None
c_ok = libvect.Vect_get_area_cats(
self.c_mapinfo, a_id, ctypes.byref(line_c)
)
if c_ok == 0: # Centroid found
ok = libvect.Vect_cat_get(
ctypes.byref(line_c), field, ctypes.byref(cat)
)
if ok > 0:
pcat = cat.value
wkb_list.append((a_id, pcat, ctypes.string_at(barray, size.value)))
libgis.G_free(barray)
return wkb_list
return None
if __name__ == "__main__":
import doctest
from grass.pygrass import utils
utils.create_test_vector_map(test_vector_name)
doctest.testmod()
"""Remove the generated vector map, if exist"""
from grass.pygrass.utils import get_mapset_vector
from grass.script.core import run_command
mset = get_mapset_vector(test_vector_name, mapset="")
if mset:
run_command("g.remove", flags="f", type="vector", name=test_vector_name)
