osm-iterator 1.5.0

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Description:

osmiterator 1.5.0

This code loads .osm file and allows to call function on all OSM objects in dataset.
Installation
pip install osm-iterator
Likely pip3 install osm-iterator if pip points to Python2 pip.
It is distributed as an osm_iterator PyPI package.

Usage example
Download data and show it
This usage example includes downloading data using requests library, that you may need to install (also available via pip).
from osm_iterator import osm_iterator
import requests
import os.path

def download_from_overpass(query, output_filepath):
print(query)
url = "http://overpass-api.de/api/interpreter"
r = requests.get(url, params={'data': query})
result = r.text
with open(output_filepath, 'w') as file:
file.write(str(result))

def show_places(element):
place_tag = element.get_tag_value("place")
name_tag = element.get_tag_value("name")
osm_object_url = element.get_link()
if place_tag != None:
print(name_tag, "(", place_tag, ") is ", osm_object_url)

filepath = "places_in_Kraków.osm"
query = """
[out:xml][timeout:2500];
area[name='Kraków']->.searchArea;
(
node["place"](area.searchArea);
way["place"](area.searchArea);
relation["place"](area.searchArea);
);
out center;
"""

if os.path.isfile(filepath) == False:
download_from_overpass(query, filepath)
osm = osm_iterator.Data(filepath)
osm.iterate_over_data(show_places)

Load data only
from osm_iterator import osm_iterator

global osm_object_store
osm_object_store = []

def record_objects(element):
global osm_object_store
print(element.element.tag, element.element.attrib['id'])
osm_object_store.append({"type": element.get_type(), "id": element.get_id()})

filepath = "output.osm"
osm = osm_iterator.Data(filepath)
osm.iterate_over_data(record_objects)
for entry in osm_object_store:
print(entry)

Running tests
nosetests3 or python3 -m unittest or python3 tests.py
History
Design explanation: this code has deeply suboptimal handling of pretty much everything. For start, all data is loaded into memory and then duplicated in-memory dataset is created.
As result, attempt to process any large datasets will cause issues due to excessive memory consumption.
This situation is consequence of following facts

This code was written during my first attempt to process OSM data using Python
API allows (at least in theory) to painlessly switch to real iterator that is not loading all data into memory at once
So far this was good enough for my purposes so I had no motivation to spend time on improving something that is not a bottleneck

Though, if someone has good ideas for improvements (especially in form of a working code) - comments and pull requests are welcomed.

License:

For personal and professional use. You cannot resell or redistribute these repositories in their original state.

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