Union filters

[arkty]

Union filters

Discussion: #1199

Problem

When developing city graph models, the size of the resulting graph might be important. Thanks to OSMnx, it's possible to use a pre-defined filters to request a network, based on desired types of OSM ways. But sometimes, it's needed to add an additional ways from OSM into network or union them based on multiple filters.

Technical details

When using custom_filter, it's not possible to request additional roads by Overpass union condition.

Example

We need to request additional road by name (The Road), ignoring all other conditions.

In Overpass this request will look like this:

(way[...](poly:'***'); way[name="The Road"](poly:'***'););

OSMnx constructs Overpass request like this, where $filter is pre-defined filter or provided by user.

[out:json][timeout:180];
(way[$filter](poly:'***');>;);
out;

Proposal

Make custom_filter accepts not only string, but a list of filters and then combine the result into single graph.
Because OSMnx already supports sub-divided requests, it's easy to implement this without changing logic on actual graph creation (simplification, connectivity, etc).

Usage example

On example of city Petrozavodsk we will use graph_from_place with network_type = "drive". This will give us a graph on a perfect level of details. But for some reason, two additional roads are required to be in model.

The request below correctly adds these roads.

ptz_graph = ox.graph_from_place(
    'Petrozavodsk, Russia',
    custom_filter=[
        op._get_network_filter("drive"),
        f'[name="улица Достоевского"]',
        f'[name="улица Калевалы"]'
    ]
)

[EwoutH]

Would something like this be possible? How would that work API wise in with this PR? (see gboeing/osmnx-examples#90)

custom_filter = '["highway"~"motorway|motorway_link"]'
construction_filter = '["construction"~"motorway|motorway_link"]'
full_filter = ???

[arkty]

@EwoutH for OR filter it will be

highway_filter = '["highway"~"motorway|motorway_link"]'
construction_filter = '["construction"~"motorway|motorway_link"]'

# Full OR filter
custom_filter = [highway_filter, construction_filter]

[EwoutH]

That’s a really clean syntax, love it!

[gboeing]

@arkty tests are failing. Run the pre-commit hooks locally then push again.

[arkty]

@gboeing i've added a commit with style fix, can you please run wf again.

[codecov]

Codecov Report

Attention: Patch coverage is 88.88889% with 1 line in your changes missing coverage. Please review.

Project coverage is 98.27%. Comparing base (8df6d7a) to head (7dca7f5).
Report is 9 commits behind head on tests.

Files	Patch %	Lines
osmnx/_overpass.py	88.88%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##            tests    #1204      +/-   ##
==========================================
- Coverage   98.31%   98.27%   -0.04%     
==========================================
  Files          24       24              
  Lines        2367     2373       +6     
==========================================
+ Hits         2327     2332       +5     
- Misses         40       41       +1     

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[EwoutH]

Awesome! Looking forward to using this in the next pre-release!