load_shapefile

This function loads a shapefile containing U.S. state geometries, applies scaling transformations to Alaska and Hawaii for proper plotting, merges electoral vote data for a specified year, and initializes columns for defecting voters. The resulting GeoDataFrame is ready for analysis or visualization.

Method Signature 

load_shapefile(year: str = "2024") -> gpd.GeoDataFrame

Parameters

year (str, optional):

The election year for which to load electoral votes. Must match a column in the electoral_votes.csv file. Defaults to "2024".

Returns

gdf (GeoDataFrame):

A GeoDataFrame containing:

  • State geometries (with Alaska and Hawaii scaled horizontally).
  • Electoral votes for the specified year (elec_votes_<year>).
  • defectors column initialized to 0.
  • defector_party column initialized to None.

Transformations Applied

  • Alaska: Horizontally scaled by a factor of 0.64 (X-axis).

  • Hawaii: Horizontally scaled by a factor of 1.1 (X-axis).

Example Usage 

import poliscipy
from poliscipy.shapefile_utils import load_shapefile

# Load the GeoDataFrame with electoral college data for 2024
gdf = load_shapefile(year="2024")

Notes

  • The shapefile must contain a STUSPS column for state abbreviations (e.g., ‘AK’, ‘HI’).
  • Scale factors were chosen to adjust Alaska and Hawaii for map visualization.
  • Defector-related columns are added to support plotting of defecting voters in electoral maps.
  • Data is safely loaded from the poliscipy.shapefiles package resources.