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Source code for script.vector

"""
Vector related functions to be used in Python scripts.

Usage:

::

    from grass.script import vector as grass
    grass.vector_db(map)

(C) 2008-2010 by the GRASS Development Team
This program is free software under the GNU General Public
License (>=v2). Read the file COPYING that comes with GRASS
for details.

.. sectionauthor:: Glynn Clements
.. sectionauthor:: Martin Landa <landa.martin gmail.com>
"""
from __future__ import absolute_import
import os
import types

try:
    import __builtin__
    bytes = str
except ImportError:
    # python3
    import builtins as __builtin__
    unicode = str

from .utils import parse_key_val
from .core import *
from grass.exceptions import CalledModuleError


[docs]def vector_db(map, **args): """Return the database connection details for a vector map (interface to `v.db.connect -g`). Example: >>> vector_db('geology') # doctest: +ELLIPSIS, +NORMALIZE_WHITESPACE {1: {'layer': 1, ... 'table': 'geology'}} :param str map: vector map :param args: other v.db.connect's arguments :return: dictionary """ s = read_command('v.db.connect', quiet=True, flags='g', map=map, sep=';', **args) result = {} for l in s.splitlines(): f = l.split(';') if len(f) != 5: continue if '/' in f[0]: f1 = f[0].split('/') layer = f1[0] name = f1[1] else: layer = f[0] name = '' result[int(layer)] = { 'layer' : int(layer), 'name' : name, 'table' : f[1], 'key' : f[2], 'database' : f[3], 'driver' : f[4] } return result
[docs]def vector_layer_db(map, layer): """Return the database connection details for a vector map layer. If db connection for given layer is not defined, fatal() is called. :param str map: map name :param layer: layer number :return: parsed output """ try: f = vector_db(map)[int(layer)] except KeyError: fatal(_("Database connection not defined for layer %s") % layer) return f # run "v.info -c ..." and parse output
[docs]def vector_columns(map, layer=None, getDict=True, **args): """Return a dictionary (or a list) of the columns for the database table connected to a vector map (interface to `v.info -c`). >>> vector_columns('geology', getDict=True) # doctest: +NORMALIZE_WHITESPACE {'PERIMETER': {'index': 2, 'type': 'DOUBLE PRECISION'}, 'GEOL250_': {'index': 3, 'type': 'INTEGER'}, 'SHAPE_area': {'index': 6, 'type': 'DOUBLE PRECISION'}, 'onemap_pro': {'index': 1, 'type': 'DOUBLE PRECISION'}, 'SHAPE_len': {'index': 7, 'type': 'DOUBLE PRECISION'}, 'cat': {'index': 0, 'type': 'INTEGER'}, 'GEOL250_ID': {'index': 4, 'type': 'INTEGER'}, 'GEO_NAME': {'index': 5, 'type': 'CHARACTER'}} >>> vector_columns('geology', getDict=False) # doctest: +NORMALIZE_WHITESPACE ['cat', 'onemap_pro', 'PERIMETER', 'GEOL250_', 'GEOL250_ID', 'GEO_NAME', 'SHAPE_area', 'SHAPE_len'] :param str map: map name :param layer: layer number or name (None for all layers) :param bool getDict: True to return dictionary of columns otherwise list of column names is returned :param args: (v.info's arguments) :return: dictionary/list of columns """ s = read_command('v.info', flags='c', map=map, layer=layer, quiet=True, **args) if getDict: result = dict() else: result = list() i = 0 for line in s.splitlines(): ctype, cname = line.split('|') if getDict: result[cname] = {'type': ctype, 'index': i} else: result.append(cname) i += 1 return result
[docs]def vector_history(map): """Set the command history for a vector map to the command used to invoke the script (interface to `v.support`). :param str map: mapname :return: v.support output """ run_command('v.support', map=map, cmdhist=os.environ['CMDLINE'])
[docs]def vector_info_topo(map, layer=1): """Return information about a vector map (interface to `v.info -t`). Example: >>> vector_info_topo('geology') # doctest: +NORMALIZE_WHITESPACE {'lines': 0, 'centroids': 1832, 'boundaries': 3649, 'points': 0, 'primitives': 5481, 'islands': 907, 'nodes': 2724, 'map3d': False, 'areas': 1832} :param str map: map name :param int layer: layer number :return: parsed output """ s = read_command('v.info', flags='t', layer=layer, map=map) ret = parse_key_val(s, val_type=int) if 'map3d' in ret: ret['map3d'] = bool(ret['map3d']) return ret
[docs]def vector_info(map, layer=1): """Return information about a vector map (interface to `v.info`). Example: >>> vector_info('geology') # doctest: +ELLIPSIS, +NORMALIZE_WHITESPACE {'comment': '', 'projection': 'Lambert Conformal Conic' ... 'south': 10875.8272320917} :param str map: map name :param int layer: layer number :return: parsed vector info """ s = read_command('v.info', flags='get', layer=layer, map=map) kv = parse_key_val(s) for k in ['north', 'south', 'east', 'west', 'top', 'bottom']: kv[k] = float(kv[k]) for k in ['level', 'num_dblinks']: kv[k] = int(kv[k]) for k in ['nodes', 'points', 'lines', 'boundaries', 'centroids', 'areas', 'islands', 'primitives']: kv[k] = int(kv[k]) if 'map3d' in kv: kv['map3d'] = bool(int(kv['map3d'])) if kv['map3d']: for k in ['faces', 'kernels', 'volumes', 'holes']: kv[k] = int(kv[k]) return kv
[docs]def vector_db_select(map, layer=1, **kwargs): """Get attribute data of selected vector map layer. Function returns list of columns and dictionary of values ordered by key column value. Example: >>> print vector_db_select('geology')['columns'] ['cat', 'onemap_pro', 'PERIMETER', 'GEOL250_', 'GEOL250_ID', 'GEO_NAME', 'SHAPE_area', 'SHAPE_len'] >>> print vector_db_select('geology')['values'][3] ['3', '579286.875', '3335.55835', '4', '3', 'Zml', '579286.829631', '3335.557182'] >>> print vector_db_select('geology', columns = 'GEO_NAME')['values'][3] ['Zml'] :param str map: map name :param int layer: layer number :param kwargs: v.db.select options :return: dictionary ('columns' and 'values') """ try: key = vector_db(map=map)[layer]['key'] except KeyError: error(_('Missing layer %(layer)d in vector map <%(map)s>') % \ {'layer': layer, 'map': map}) return {'columns': [], 'values': {}} include_key = True if 'columns' in kwargs: if key not in kwargs['columns'].split(','): # add key column if missing include_key = False debug("Adding key column to the output") kwargs['columns'] += ',' + key ret = read_command('v.db.select', map=map, layer=layer, **kwargs) if not ret: error(_('vector_db_select() failed')) return {'columns': [], 'values': {}} columns = [] values = {} for line in ret.splitlines(): if not columns: columns = line.split('|') key_index = columns.index(key) # discard key column if not include_key: columns = columns[:-1] continue value = line.split('|') key_value = int(value[key_index]) if not include_key: # discard key column values[key_value] = value[:-1] else: values[key_value] = value return {'columns': columns, 'values': values}
json = None orderedDict = None
[docs]def vector_what(map, coord, distance=0.0, ttype=None, encoding=None, skip_attributes=False, layer=None, multiple=False): """Query vector map at given locations To query one vector map at one location :: print grass.vector_what(map='archsites', coord=(595743, 4925281), distance=250) [{'Category': 8, 'Map': 'archsites', 'Layer': 1, 'Key_column': 'cat', 'Database': '/home/martin/grassdata/spearfish60/PERMANENT/dbf/', 'Mapset': 'PERMANENT', 'Driver': 'dbf', 'Attributes': {'str1': 'No_Name', 'cat': '8'}, 'Table': 'archsites', 'Type': 'Point', 'Id': 8}] To query one vector map with multiple layers (no additional parameters required) :: for q in grass.vector_what(map='some_map', distance=100.0, coord=(596532.357143,4920486.21429)): print q['Map'], q['Layer'], q['Attributes'] new_bug_sites 1 {'str1': 'Beetle_site', 'GRASSRGB': '', 'cat': '80'} new_bug_sites 2 {'cat': '80'} To query more vector maps at one location :: for q in grass.vector_what(map=('archsites', 'roads'), coord=(595743, 4925281), distance=250): print q['Map'], q['Attributes'] archsites {'str1': 'No_Name', 'cat': '8'} roads {'label': 'interstate', 'cat': '1'} To query one vector map at more locations :: for q in grass.vector_what(map='archsites', distance=250, coord=[(595743, 4925281), (597950, 4918898)]): print q['Map'], q['Attributes'] archsites {'str1': 'No_Name', 'cat': '8'} archsites {'str1': 'Bob_Miller', 'cat': '22'} :param map: vector map(s) to query given as string or list/tuple :param coord: coordinates of query given as tuple (easting, northing) or list of tuples :param distance: query threshold distance (in map units) :param ttype: list of topology types (default of v.what are point, line, area, face) :param encoding: attributes encoding :param skip_attributes: True to skip quering attributes :param layer: layer number or list of layers (one for each vector), if None, all layers (-1) are used :param multiple: find multiple features within threshold distance :return: parsed list """ if "LC_ALL" in os.environ: locale = os.environ["LC_ALL"] os.environ["LC_ALL"] = "C" if isinstance(map, (bytes, unicode)): map_list = [map] else: map_list = map if layer: if isinstance(layer, (tuple, list)): layer_list = [str(l) for l in layer] else: layer_list = [str(layer)] if len(layer_list) != len(map_list): raise ScriptError(_("Number of given vector maps ({m}) " "differs from number of layers ({l})").format(m=len(map_list), l=len(layer_list))) else: layer_list = ['-1'] * len(map_list) coord_list = list() if isinstance(coord, tuple): coord_list.append('%f,%f' % (coord[0], coord[1])) else: for e, n in coord: coord_list.append('%f,%f' % (e, n)) flags = 'j' if not skip_attributes: flags += 'a' if multiple: flags += 'm' cmdParams = dict(quiet=True, flags=flags, map=','.join(map_list), layer=','.join(layer_list), coordinates=','.join(coord_list), distance=float(distance)) if ttype: cmdParams['type'] = ','.join(ttype) try: ret = read_command('v.what', **cmdParams).strip() except CalledModuleError as e: raise ScriptError(e.msg) if "LC_ALL" in os.environ: os.environ["LC_ALL"] = locale data = list() if not ret: return data # lazy import global json global orderedDict if json is None: import json if orderedDict is None: try: from collections import OrderedDict orderedDict = OrderedDict except ImportError: orderedDict = dict kwargs = {} if encoding: kwargs['encoding'] = encoding if sys.version_info[0:2] > (2, 6): kwargs['object_pairs_hook'] = orderedDict try: result = json.loads(ret, **kwargs) except ValueError: raise ScriptError(_("v.what output is not valid JSON format:\n {ret}").format(ret=ret)) if multiple: for vmap in result['Maps']: features = vmap.pop('Features', None) if features: for feature in features: cats = feature.pop('Categories', None) if cats: for cat in cats: tmp = feature.copy() tmp.update(cat) tmp2 = vmap.copy() tmp2.update(tmp) data.append(tmp2) else: for vmap in result['Maps']: cats = vmap.pop('Categories', None) if cats: for cat in cats: tmp = vmap.copy() tmp.update(cat) data.append(tmp) else: data.append(vmap) return data

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