import pandas as pd
from geopandas import GeoDataFrame
from shapely.geometry import box

df = pd.read_csv("~/Downloads/rectangles.csv")
b = df.apply(lambda row: box(row.west_lon, row.south_lat, row.east_lon, row.north_lat), axis=1)
gdf = geopandas.GeoDataFrame(df, geometry=b)
gdf['geometry'] = [g.wkt for g in gdf['geometry'].values]
gdf.to_csv('~/Downloads/rectangle_polygons.csv', index=False)