wghh-zensus-api

A simple flask app that serves an api endpoint to obtain flats ownership statistics for addresses in Hamburg, Germany.

It turns a given adress into coordinates and then looks up the corresponding 100m square grid from the Zensus11 Wohnungen & Gebäude dataset.

To obtain the coordinates, it first looks into the ALKIS Adressen Hamburg dataset.

As a fallback, it uses Nominatim as a geocoder to obtain coordinates.

It also provides an autocomplete endpoint for suggesting street names.

install

pip install -r requirements.txt

local run

FLASK_DEBUG=1 FLASK_APP=app.py flask run

this will fire up a local webserver at 127.0.0.1:5000

query

The endpoint expects two self-explanatory GET parameters:

• street
• nr

It returns a json dictionary with the key data that is either null or full of data plus an additional key match that shows info about the exactness of the result

suggest

the endpoint /suggest expects a GET parameter named q. It will search the database against street names starting with this value.

It returns a json dictionary with the key data that is a list of street names (that may be empty if nothing is found).

examples

Query for "Sievekingsallee 3":

http://127.0.0.1:5000/?street=Sievekingsallee&nr=3

the result:

{
  "data": {
    "flats_cooperative_owned": 26,
    "flats_cooperative_owned_q": 21,
    "flats_ngo_church_owned": 0,
    "flats_ngo_church_owned_q": 0,
    "flats_other_private_company_owned": 0,
    "flats_other_private_company_owned_q": 0,
    "flats_private_company_owned": 0,
    "flats_private_company_owned_q": 0,
    "flats_private_owned": 94,
    "flats_private_owned_q": 78,
    "flats_public_body_owned": 0,
    "flats_public_body_owned_q": 0,
    "flats_state_owned": 0,
    "flats_state_owned_q": 0,
    "flats_total": 120,
    "id": "100mN33834E43253"
  },
  "match": "street"
}

Autocomplete street names starting with "müg":

http://127.0.0.1:5000/suggest?q=müg

the result:

{
  "data": [
    "M\u00fcggenburg",
    "M\u00fcggenburger Hauptdeich",
    "M\u00fcggenburger Stra\u00dfe",
    "M\u00fcggenkampstra\u00dfe",
    "M\u00fcggenloch"
  ]
}