def read_osm(osm_file_path, osm_read_config, num_processes: int = 1, epsg=None):
"""
Reads OSM data into a graph of the Network object
:param osm_file_path: path to .osm or .osm.pbf file
:param osm_read_config: config file (see configs folder in genet for examples) which informs for example which
highway types to read (in case of road network) and what modes to assign to them
:param num_processes: number of processes to split parallelisable operations across
:param epsg: projection for the output Network, e.g. 'epsg:27700'. If not provided, defaults to epsg:4326
:return: genet.Network object
"""
if epsg is None:
epsg = 'epsg:4326'
config = osm_reader.Config(osm_read_config)
n = core.Network(epsg)
nodes, edges = osm_reader.generate_osm_graph_edges_from_file(
osm_file_path, config, num_processes)
nodes_and_attributes = parallel.multiprocess_wrap(
data=nodes,
split=parallel.split_dict,
apply=osm_reader.generate_graph_nodes,
combine=parallel.combine_dict,
epsg=epsg,
processes=num_processes
)
reindexing_dict, nodes_and_attributes = n.add_nodes(nodes_and_attributes, ignore_change_log=True)
edges_attributes = parallel.multiprocess_wrap(
data=edges,
split=parallel.split_list,
apply=osm_reader.generate_graph_edges,
combine=parallel.combine_list,
reindexing_dict=reindexing_dict,
nodes_and_attributes=nodes_and_attributes,
config_path=osm_read_config,
processes=num_processes
)
n.add_edges(edges_attributes, ignore_change_log=True)
logging.info('Deleting isolated nodes which have no edges.')
n.remove_nodes(list(nx.isolates(n.graph)))
return n
def slim_default_config():
return osm_reader.Config(
os.path.join(os.path.dirname(__file__), "..", "configs",
"slim_config.yml"))
def full_fat_default_config():
return osm_reader.Config(
os.path.abspath(
os.path.join(os.path.dirname(__file__), "..", "configs",
"default_config.yml")))