How to map a point to a polygon label from a shapefile

Question

I have a shapefile that breaks the city of San Francisco up into a number of different districts depending on who your supervisor is.

I need to make a lookup tool that takes a single long lat value and says which supervisor district the point lies in. The supervisor district is one of the attributes of the shapefile.

How would I go about doing this in an efficient manner?

Edit 1: Seems like something like this is what I'm looking for. Trying to figure out how I access the attributes once an intersection is found

Answer 1

I ended up doing it this way. The shapefile was too small for an rtree to make any difference in speed:

import fiona
from shapely.geometry import Point, shape

def long_lat_to_district(longit, lat, shape_file):

    mypoint = Point(longit, lat)   

    with fiona.open(shape_file) as shp:
        polygons = [poly for poly in shp]

    poly_idx = [i for i, poly in enumerate(polygons)
                if mypoint.within(shape(poly['geometry']))]

    if not poly_idx:
        return None
    else:
        # Take first polygon that overlaps since may overlap with several if on border
        match = polygons[poly_idx[0]]
        return match['properties']