crossnm 0.2.2

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CrossNM

Python package for downloading, and caching network rail geometry models as GeoPandas GeoDataFrames.

What this package provides

CrossNM has two network model views, both of which use "EPSG: 27700" (https://epsg.io/27700) as a coordinate reference system:

• Full model

• Simplified model: produces a single-line representation of the network and is not split by ELR.

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Installation

pip install crossnm

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Quick start

from crossnm import FullModel, SimplifiedModel

tracks_gdf = FullModel(hasLogs=False).download() # Entire network model loaded, logs are suppressed

subsection_gdf = FullModel().download_many(["AAV","GAE"]) # Subset of ELRs are selected from Entire network model

simplified_tracks_gdf = SimplifiedModel().download()

Cache Behaviour

When available, FullModel().download() will load relevant geometries from a local cache. This is created when the geometry was last downloaded.

The GeoDataFrames are stored as .pkl files alongside cache information as a .json. The cache .json contains information on the life-span of the cache as a unix timestamp, as well as when the geometry was last cached.

On loading the geometry, the cache information is inspected, and if the cache is out of date, the geometry is replaced with a download from the google storage bucket. The cache information is then updated with the new time of cacheing.

Logs

If logs are not required, pass hasLogs=False into the constructor of the loader.