pygrass package¶
Subpackages¶
- pygrass.gis package
- pygrass.messages package
- pygrass.modules package
- Subpackages
- pygrass.modules.grid package
- pygrass.modules.interface package
- Submodules
- pygrass.modules.interface.docstring module
- pygrass.modules.interface.env module
- pygrass.modules.interface.flag module
- pygrass.modules.interface.module module
- pygrass.modules.interface.parameter module
- pygrass.modules.interface.read module
- pygrass.modules.interface.typedict module
- Module contents
- Submodules
- pygrass.modules.shortcuts module
- Module contents
- Subpackages
- pygrass.raster package
- pygrass.rpc package
- pygrass.shell package
- pygrass.tests package
- pygrass.vector package
Submodules¶
pygrass.errors module¶
pygrass.orderdict module¶
pygrass.utils module¶
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pygrass.utils.
coor2pixel
(coord, region)[source]¶ Convert coordinates into a pixel row and col
>>> from grass.pygrass.gis.region import Region >>> reg = Region() >>> coor2pixel((reg.west, reg.north), reg) (0.0, 0.0) >>> coor2pixel((reg.east, reg.south), reg) == (reg.rows, reg.cols) True
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pygrass.utils.
copy
(existingmap, newmap, maptype, **kwargs)[source]¶ Copy a map
>>> copy(test_vector_name, 'mycensus', 'vector') >>> rename('mycensus', 'mynewcensus', 'vector') >>> remove('mynewcensus', 'vector')
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pygrass.utils.
create_test_stream_network_map
(map_name='streams')[source]¶ Create test data
This functions creates a vector map layer with lines that represent a stream network with two different graphs. The first graph contains a loop, the second can be used as directed graph.
This should be used in doc and unit tests to create location/mapset independent vector map layer.
param map_name: The vector map name that should be used- 1(0,2) 3(2,2)
- /
- 1 / 2
- /
- 2(1,1)
- 6(0,1) || 5(2,1)
- 5 || / 4
- ||/
- 4(1,0) | | 6 |7(1,-1)
- 7(0,-1) 8(2,-1)
- /
- 8 / 9
- /
- 9(1, -2) | | 10 |
10(1,-3)
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pygrass.utils.
create_test_vector_map
(map_name='test_vector')[source]¶ This functions creates a vector map layer with points, lines, boundaries, centroids, areas, isles and attributes for testing purposes
This should be used in doc and unit tests to create location/mapset independent vector map layer. This map includes 3 points, 3 lines, 11 boundaries and 4 centroids. The attribute table contains cat, name and value columns.
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pygrass.utils.
decode
(obj, encoding=None)[source]¶ Decode string coming from c functions, can be ctypes class String, bytes, or None
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pygrass.utils.
findmaps
(type, pattern=None, mapset='', location='', gisdbase='')[source]¶ Return a list of tuple contining the names of the:
- map
- mapset,
- location,
- gisdbase
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pygrass.utils.
get_lib_path
(modname, libname=None)[source]¶ Return the path of the libname contained in the module.
Deprecated since version 7.1: Use
grass.script.utils.get_lib_path()
instead.
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pygrass.utils.
get_mapset_raster
(mapname, mapset='')[source]¶ Return the mapset of the raster map
>>> get_mapset_raster(test_raster_name) == getenv("MAPSET") True
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pygrass.utils.
get_mapset_vector
(mapname, mapset='')[source]¶ Return the mapset of the vector map
>>> get_mapset_vector(test_vector_name) == getenv("MAPSET") True
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pygrass.utils.
get_raster_for_points
(poi_vector, raster, column=None, region=None)[source]¶ Query a raster map for each point feature of a vector
Example
>>> from grass.pygrass.raster import RasterRow >>> from grass.pygrass.gis.region import Region >>> from grass.pygrass.vector import VectorTopo >>> from grass.pygrass.vector.geometry import Point
Create a vector map
>>> cols = [(u'cat', 'INTEGER PRIMARY KEY'), ... (u'value', 'double precision')] >>> vect = VectorTopo("test_vect_2") >>> vect.open("w",tab_name="test_vect_2", ... tab_cols=cols) >>> vect.write(Point(10, 6), cat=1, attrs=[10, ]) >>> vect.write(Point(12, 6), cat=2, attrs=[12, ]) >>> vect.write(Point(14, 6), cat=3, attrs=[14, ]) >>> vect.table.conn.commit() >>> vect.close()
Setup the raster sampling
>>> region = Region() >>> region.from_rast(test_raster_name) >>> region.set_raster_region() >>> ele = RasterRow(test_raster_name)
Sample the raster layer at the given points, return a list of values
>>> l = get_raster_for_points(vect, ele, region=region) >>> l[0] # doctest: +ELLIPSIS (1, 10.0, 6.0, 1) >>> l[1] # doctest: +ELLIPSIS (2, 12.0, 6.0, 1)
Add a new column and sample again
>>> vect.open("r") >>> vect.table.columns.add(test_raster_name,'double precision') >>> vect.table.conn.commit() >>> test_raster_name in vect.table.columns True >>> get_raster_for_points(vect, ele, column=test_raster_name, region=region) True >>> vect.table.filters.select('value', test_raster_name) Filters('SELECT value, Utils_test_raster FROM test_vect_2;') >>> cur = vect.table.execute() >>> r = cur.fetchall() >>> r[0] # doctest: +ELLIPSIS (10.0, 1.0) >>> r[1] # doctest: +ELLIPSIS (12.0, 1.0) >>> remove('test_vect_2','vect')
Parameters: - poi_vector – A VectorTopo object that contains points
- raster – raster object
- column (str) – column name to update in the attrinute table, if set to None a list of sampled values will be returned
- region – The region to work with, if not set the current computational region will be used
Returns: True in case of success and a specified column for update, if column name for update was not set a list of (id, x, y, value) is returned
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pygrass.utils.
getenv
(env)[source]¶ Return the current grass environment variables
>>> from grass.script.core import gisenv >>> getenv("MAPSET") == gisenv()["MAPSET"] True
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pygrass.utils.
is_clean_name
(name)[source]¶ Return if the name is valid
>>> is_clean_name('census') True >>> is_clean_name('0census') True >>> is_clean_name('census?') True >>> is_clean_name('cénsus') False
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pygrass.utils.
looking
(obj, filter_string)[source]¶ >>> import grass.lib.vector as libvect >>> sorted(looking(libvect, '*by_box*')) # doctest: +NORMALIZE_WHITESPACE ['Vect_select_areas_by_box', 'Vect_select_isles_by_box', 'Vect_select_lines_by_box', 'Vect_select_nodes_by_box']
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pygrass.utils.
pixel2coor
(pixel, region)[source]¶ Convert row and col of a pixel into a coordinates
>>> from grass.pygrass.gis.region import Region >>> reg = Region() >>> pixel2coor((0, 0), reg) == (reg.north, reg.west) True >>> pixel2coor((reg.cols, reg.rows), reg) == (reg.south, reg.east) True
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pygrass.utils.
set_path
(modulename, dirname=None, path='.')[source]¶ Set sys.path looking in the the local directory GRASS directories.
Parameters: - modulename – string with the name of the GRASS module
- dirname – string with the directory name containing the python libraries, default None
- path – string with the path to reach the dirname locally.
Deprecated since version 7.1: Use
grass.script.utils.set_path()
instead.
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pygrass.utils.
split_in_chunk
(iterable, length=10)[source]¶ Split a list in chunk.
>>> for chunk in split_in_chunk(range(25)): print (chunk) (0, 1, 2, 3, 4, 5, 6, 7, 8, 9) (10, 11, 12, 13, 14, 15, 16, 17, 18, 19) (20, 21, 22, 23, 24) >>> for chunk in split_in_chunk(range(25), 3): print (chunk) (0, 1, 2) (3, 4, 5) (6, 7, 8) (9, 10, 11) (12, 13, 14) (15, 16, 17) (18, 19, 20) (21, 22, 23) (24,)