warningdata module

Framework to import, cache, and use flood warning and corresponding data.

warningdata.build_regions_geojson(warnings, file=None)

Create geoJSON FeatureCollection object to plot flood warnings on a map.

Parameters

  • warnings (list[FloodWarning]) – List of flood warnings.

  • file (string, optional) – For debug purposes, saves parameters data to a file, without any coordinates if file is a non-None string. The default is None.

Returns

data – The geoJSON object containing the regions of all the warnings in warnings.

Return type

dict

warningdata.build_severity_dataframe(warnings)

Build dataframe with warnings data, used to colour the map regions.

Parameters

warnings (list[FloodWarning]) – list of flood warnings.

Returns

df – Pandas DataFrame with the relevant data for each warning

Return type

pandas.DataFrame

warningdata.build_warning_list(severity, use_pickle_caches=True, progress_bar=False)

Fetch warnings from the API and create a list of warnings.

Also updates caches for flood regions for any new warnings.

Parameters

  • severity (int) – warnings above this minimum severity value (ie of lower numerical value) will be returned.

  • use_pickle_caches (bool, optional) – If true, then cached data regarding flood regions is used - the flood warnings are still the most recent pulled from the API. The default is True.

  • progress_bar (bool, optional) – If supplied, creates a bar in the terminal and updates as the warning list is built. The defualt is False

Returns

warnings – The list of FloodWarning objects of severity greater than or equal to severity.

Return type

list[FloodWarning]

warningdata.retrieve_pickle_cache(filename)

Read a cached pickle file and returns the result.

Parameters

filename (string) – The name of the pickle file to be read. This file must be in the cache directory.

Returns

The python variables read from the pickle file..

Return type

pickle_variables

warningdata.save_to_pickle_cache(filename, data)

Save data to a pickle cache file.

Parameters

  • filename (string) – The name of the pickle file to be saved. The file is placed in the cache directory.

  • data – The data to be saved to a pickle file. Any Python variable type may be used.

Returns

Return type

None.

warningdata.update_poly_area_caches(warnings, poly_cache='warning_polys.pk', area_cache='warning_areas.pk', overwrite=False)

Create updated lists of polygons/areas pertaining to any new warnings.

If previous cached data is available, and overwrite is false the new data is appended to this. polygon data is stored as a list of lists containing four attributes for each warning: [[geojson, region, is_poly_simplified, simplified_geojson], …]

area data is stored as a list of json objects obtained from the API for each warning: [[area_json], …]

Parameters

  • warnings (list[FLoodWarnings]) – The list of FloodWarning objects of severity greater than or equal to severity.

  • poly_cache (string, optional) – The name of the polygon cache file. The default is ‘warning_polys.pk’.

  • area_cache (string, optional) – The name of the area cache file. The default is ‘warning_areas.pk’.

  • overwrite (bool, optional) –

    If True, previously cached data is overwritten and only current data is

    added to the cache files. The default is False.

Returns

Return type

None.