pghelpers module

tripsender.pghelpers.amenity_from_kml(mypath)

A function to fetch all kml data from a folder containing KML files.

Parameters

mypath – (str) A string containing the directory path to a folder with KML files

Returns

(GeoPandas GeoDataFrame) A GDF of amenity lat and lon

tripsender.pghelpers.flatten_gdf(gdf)

A utility function to flatten the nested hierarchy of a GeoPandas GeoDataFrame.

Parameters

gdf – (GeoPandas GeoDataFrame) A GDF to flatten

Returns

(GeoPandas GeoDataFrame) A flattened GDF

tripsender.pghelpers.get_amenities(gdf, amenity)

A function to fetch amenities using a keyword from the OpenStreetMaps Overpass api. (not recommended!) Use overpass turbo to help frame the keywords.

Parameters

  • gdf – (GeoPandas GeoDataFrame) A GDF containing the origins of homes

  • amenity – (str) A query string formatted for the OSM overpass API. (See overpass turbo)

Returns

(GeoPandas GeoDataFrame)

tripsender.pghelpers.get_closest_from_kml(kmlPath, gdfAgentHomes)

A function to return a GDF of matched closest amenities from a KML directory and a GDF of agent origins/homes.

Parameters

  • kmlPath – (str) A string containing the directory path to a folder with KML files

  • gdfAgentHomes – (GeoPandas GeoDataFrame) A GeoDataFrame containing an origin column with point geometry.

Returns

(GeoPandas GeoDataFrame, list) A GDF containing the matched closest amenities and a list of amenity names

tripsender.pghelpers.get_gdf(area, feature, KEY='', VAL='', title='Data from Server', filter=False, local=True, web=True, plot=False)

A function to fetch spatial geometry from the PostGIS server as GeoPandas GeoDataFrame. This function is simply a wrapper for the psycopg2 module. It constructs an SQL query based on the the params provided and requests data from the server.

Parameters

  • area – (str) The name of the Primary area in the Model naming format.

  • feature – (str) The feature name to select from the PostGIS database. (Refer to PostGIS naming convention)

  • KEY – (str: Optional) An optional attribute to filter from the data at the server level

  • VAL – (str: Optional) An optional value for a given key to match from the data at the server level

  • title – (str: Optional) An optional title for the plot

  • filter – (bool: Optional) An optional input to specify if the data must be filtered at the server level

  • local – (bool: Optional) Which server to fetch the data from

  • web – (bool: Optional) If True, the result will be reprojected

  • plot – (bool: Optional) If True, the result will be plotted

Returns

(GeoPandas GeoDataFrame, plot(Optional)) The resulting GeoPandas GeoDataFrame.

tripsender.pghelpers.get_nearest_amenity(gdA, gdfAmenity, amenityList)

A function to get the nearest amenities from a source and destination GDF.

Parameters

  • gdA – (GeoPandas GeoDataFrame) A GDF with the origins of homes

  • gdfAmenity – (GeoPandas GeoDataFrame) A GDF containing the amenities with a unique name for each amenity

  • amenityList – (list) A list of amenity names as string

Returns

tripsender.pghelpers.get_pg_query(sql, local=True, web=True)

A utility function that fetches any data using an SQL query from the PostGIS Server This function is a basic wrapper for the psycopg2 module with secrets included.

Parameters

  • sql – (str) An SQL query string

  • local – (bool: Optional) If True, data will be fetched from the local server

  • web – (bool: Optional) If True, result will be reprojected to EPSG:4326

Returns

tripsender.pghelpers.get_pg_route(source, target, plot=True, local=True)

A function to perform routing on the PostGIS server using PG_Routing.

Parameters

  • source – (tuple) A coordinate of the source point for routing

  • target – (tuple) A coordinate of the destination point for routing

  • plot – (bool: Optional) If True, the result will be plotted

  • local – (bool: Optional) If True, data will be fetched from the local server

Returns

(list) A list of tuples representing the nodes along the shortest path from source to target

tripsender.pghelpers.get_random_source(gdfAgentHomes)

A function to select a random source from a GeoPandas GeoDataframe.

Parameters

gdfAgentHomes – (GeoPandas GeoDataFrame) A Geodataframe containing an origin column with point geometry.

Returns

(tuple) Coordinates as a tuple

tripsender.pghelpers.get_road(local=True, web=True, ped=True)

A function that is hardcoded to only fetch the complete street network as a GeoPandas GeoDataFrame. :param local: (bool: Optional) If True, data will be fetched from the local server :param web: (bool: Optional) If True, result will be reprojected to EPSG:4326 :param ped: (bool: Optional) If True, data will be fetched for the pedestrian network, else car network. :return: (GeoPandas GeoDataFrame) A GDF containing the entire street network on the PostGIS server.

tripsender.pghelpers.plot_gdf_pretty(gdf, column=None, figsize=(10, 10), legend=False)

A function that plots the GeoDataFrame using the contextily library against a map background.

Parameters

  • gdf – (GeoPandas GeoDataFrame) GDF to be plotted

  • column – (str: Optional) Name of the column to be plotted

  • figsize – (tuple: Optional)

  • legend – (bool: Optional)

Returns

(Plot)