Implement rate limiting according to Nominatim Usage Policy

README.md

@@ -56,7 +56,7 @@ A run without cache takes some time as it fetches all data from their sources:
 1. Get a list of countries in Europe and federal states in Germany from [Wikidata](https://wikidata.org).
 1. Download all these countries' and states' border shapes from Wikimedia Commons.
 1. Get a list of Erfas & Chaostreffs from the doku.ccc.de Semantic Mediawiki API.
-1. Resolve all POIs' (Erfas & Chaostreffs) street addresses' to geocoordinates using [Nominatim](https://nominatim.org/).
+1. Resolve all POIs' (Erfas & Chaostreffs) street addresses' to geocoordinates using [Nominatim](https://nominatim.org/), rate limited to 1 request per second as per Nominatims usage policy.
 
 **Use the cache whenevery you don't need to update country borders or hackerspace locations.  Otherwise, both Wikidata and Nominatim will start rate limiting pretty quickly.** (And caching is actually required by [Nominatim's acceptable use policy](https://operations.osmfoundation.org/policies/nominatim/)).
 

generate_map.py

@@ -17,6 +17,7 @@ import math
 from lxml import etree
 import pyproj
 from geopy import Nominatim
+from geopy.extra.rate_limiter import RateLimiter
 import tqdm
 import cairosvg
 from PIL import Image, ImageFont
@@ -282,7 +283,10 @@ class Erfa(Drawable):
 
     @classmethod
     def address_lookup(cls, attr):
-        locator = Nominatim(user_agent=USER_AGENT)
+        # Nominatim's Usage Policy requires rate limiting to 1 request per seconds
+        nominatim = Nominatim(user_agent=USER_AGENT)
+        geocode = RateLimiter(nominatim.geocode, min_delay_seconds=1)
+
         number = attr['Chaostreff-Physical-Housenumber']
         street = attr['Chaostreff-Physical-Address']
         zipcode = attr['Chaostreff-Physical-Postcode']
@@ -303,7 +307,7 @@ class Erfa(Drawable):
             formats.insert(0, f'{street[0]} {number[0]}, {zipcode[0]} {acity[0]}, {country}')
 
         for fmt in formats:
-            response = locator.geocode(fmt)
+            response = geocode(fmt)
             if response is not None:
                 return response.longitude, response.latitude
 
@@ -384,7 +388,6 @@ class Erfa(Drawable):
                         erfa = cls.from_api(ns, name, attr['printouts'], radius)
                         erfas.append(erfa)
                     except BaseException as e:
-                        breakpoint()
                         print(e)
                         continue