BBBikeReader.merge_shp_layers

BBBikeReader.merge_shp_layers(subregion_names, layer_name, data_dir=None, engine='pyshp', update=False, download=False, rm_zip_extracts=True, merged_shp_dir=None, rm_shp_temp=True, verbose=False, ret_merged_shp_path=False)

Merge shapefiles for a specific layer of two or multiple geographic regions.

Parameters:

• subregion_names (list) – names of geographic region (case-insensitive) that is available on Geofabrik free download server

• layer_name (str) – name of a layer (e.g. ‘railways’)

• engine (str) – the method used to merge/save shapefiles; options include: 'pyshp' (default) and 'geopandas' (or 'gpd') if engine='geopandas', this function relies on geopandas.GeoDataFrame.to_file(); otherwise, it by default uses shapefile.Writer()

• update (bool) – whether to update the source .shp.zip files, defaults to False

• download (bool) – whether to ask for confirmation before starting to download a file, defaults to True

• data_dir (str | None) – directory where the .shp.zip data files are located/saved; if None (default), the default directory

• rm_zip_extracts (bool) – whether to delete the extracted files, defaults to False

• rm_shp_temp (bool) – whether to delete temporary layer files, defaults to False

• merged_shp_dir (str | None) – if None (default), use the layer name as the name of the folder where the merged .shp files will be saved

• verbose (bool | int) – whether to print relevant information in console, defaults to False

• ret_merged_shp_path (bool) – whether to return the path to the merged .shp file, defaults to False

Returns:

the path to the merged file when ret_merged_shp_path=True

Return type:

list | str

Examples:

>>> from pydriosm.reader import BBBikeReader
>>> from pyhelpers.dirs import cd, delete_dir
>>> import os

>>> bbr = BBBikeReader()

Example 1:

>>> # To merge 'railways' of London and Birmingham
>>> subrgn_name = ['London', 'Birmingham']
>>> lyr_name = 'railways'
>>> dat_dir = "tests/osm_data"
>>> path_to_merged_shp_file = bbr.merge_shp_layers(
...     subrgn_name, lyr_name, dat_dir, verbose=True, ret_merged_shp_path=True)
Proceed to download data in the format '.shp.zip' for the following geographic (sub...
    "London"
    "Birmingham"
  to "./tests/osm_data/"
? [No]|Yes: yes
Downloading "London.osm.shp.zip" 100%|██████████| 248M/248M | 16.5MB/s | ETA:...
  Saving "London.osm.shp.zip" to "./tests/osm_data/london/" ... Done.
Downloading "Birmingham.osm.shp.zip" 100%|██████████| 79.1M/79.1M | 16.9MB/s ...
  Saving "Birmingham.osm.shp.zip" to "./tests/osm_data/birmingham/" ... Done.
Merging the following shapefiles:
  "london_railways.shp"
  "birmingham_railways.shp"
  In progress ... Done.
    Find the merged shapefile in "./tests/osm_data/lon-bir-railways/".

>>> path_to_merged_shp_file = path_to_merged_shp_file[0]
>>> os.path.relpath(path_to_merged_shp_file)
'tests\osm_data\lon-bir-railways\lon-bir-railways.shp'

>>> # Read the merged data
>>> lon_bir_railways_shp = bbr.SHP.read_shp(path_to_merged_shp_file)
>>> lon_bir_railways_shp.head()
   osm_id  ...                                           geometry
0   30804  ...     LINESTRING (0.00486 51.62793, 0.0062 51.62927)
1  101298  ...  LINESTRING (-0.22499 51.4937, -0.22516 51.4945...
2  101486  ...  LINESTRING (-0.20555 51.51954, -0.20514 51.519...
3  101511  ...  LINESTRING (-0.2119 51.52419, -0.21081 51.5239...
4  282898  ...   LINESTRING (-0.1862 51.61592, -0.18687 51.61386)
[5 rows x 4 columns]

>>> # Delete the merged files
>>> delete_dir(os.path.dirname(path_to_merged_shp_file), verbose=True)
To delete the directory "./tests/osm_data/lon-bir-railways/" (Not empty)
? [No]|Yes: yes
Deleting "./tests/osm_data/lon-bir-railways/" ... Done.

>>> # Delete the downloaded .shp.zip data files
>>> delete_dir(list(map(os.path.dirname, bbr.downloader.data_paths)), verbose=True)
To delete the following directories:
  "./tests/osm_data/london/" (Not empty)
  "./tests/osm_data/birmingham/" (Not empty)
? [No]|Yes: yes
Deleting:
  "./tests/osm_data/london/" ... Done.
  "./tests/osm_data/birmingham/" ... Done.

>>> # Delete the example data and the test data directory
>>> delete_dir(dat_dir, verbose=True)
To delete the directory "./tests/osm_data/" (Not empty)
? [No]|Yes: yes
Deleting "./tests/osm_data/" ... Done.