Competitor walksheds

A coffee shop wants to know which competitors draw from the same neighbourhood it does. Its walkshed is every residential block that can walk to it. This tutorial finds nearby competitors and measures how much of that walkshed they share. The example city is Providence, Rhode Island.

Running this tutorial uses about 900 tokens.

Set up

Read the cafe category id from the free catalog and find the city centre.

from closecity import Client

close = Client("ck_live_your_key")   # use your own key here

types = close.destination_types()
ids = dict(zip(types["label"], types["dest_type_id"]))
cafe = ids["cafes"]

city = close.places("Providence").iloc[0]

Find the shops

Search for cafes near downtown. The result is a GeoDataFrame of points, so plot them and pick one shop as the subject.

cafes = close.pois_search(lat = city["lat"], lon = city["lon"],
                          radius_m = 1200, type = cafe)
cafes.plot(color = "#202a5b")

ours = cafes.iloc[0]
ours["name"]

'The Nitro Bar'

Our walkshed

Ask for every block that can reach our shop within a 10-minute walk. This comes back as polygons, with the block boundaries downloaded by pygris.

our_shed = close.poi_catchment(int(ours["dest_id"]), mode = "walk",
                               max_minutes = 10)
our_geoids = set(our_shed.geoid)

ax = our_shed.plot(color = "#eef0f7", edgecolor = "#c6cbe0")
cafes.iloc[[0]].plot(ax = ax, color = "#f36e21", markersize = 60)

<Axes: >

Who else serves it

For each of the nearest competitors, pull their walkshed and count the blocks they share with ours. Both walksheds are just sets of block ids, so the overlap is a plain set intersection.

for i in range(1, 6):
    competitor = cafes.iloc[i]
    their_shed = close.poi_catchment(int(competitor["dest_id"]), mode = "walk",
                                     max_minutes = 10)
    shared = our_geoids & set(their_shed.geoid)
    print(f"{competitor['name']:28} {len(shared):3} shared blocks "
          f"({len(shared) / len(our_shed):.0%} of ours)")

Schaste                      120 shared blocks (83% of ours)

White Electric                79 shared blocks (54% of ours)

Starbucks                     83 shared blocks (57% of ours)

Little City Coffee & Kitchen  22 shared blocks (15% of ours)

Cafe La France                 1 shared blocks (1% of ours)

Map the contested ground

Draw our walkshed, then every cafe on top, with our shop highlighted.

ax = our_shed.plot(color = "#eef0f7", edgecolor = "#c6cbe0")
cafes.plot(ax = ax, color = "#202a5b")
cafes.iloc[[0]].plot(ax = ax, color = "#f36e21", markersize = 60)

<Axes: >

The same recipe works over a wider area: search a bounding box instead of a radius, and loop over more shops.