Finding a Weather Station

You can get a list of all the Weather Stations that are currently online, using a simple URL. This is because the database that all the Weather Stations upload data to has a RESTful API. This is a method by which you can write code that uses simple HTTP requests (just like a browser) to fetch the data.

Copy and paste the following URL into a web browser:

https://apex.oracle.com/pls/apex/raspberrypi/weatherstation/getallstations

data from weather stations in webpage

You should see a web page filled with data. This is a little difficult to read, though. Luckily, we can grab this data with a little Python code and then present it in a format that’s easier to read.

  • Open IDLE Python 3 to open the Python shell

  • Open a new file by clicking File > New File.

  • Save your program as fetch_stations.py.

  • The first thing you’ll need is a few Python modules. requests is not in the standard library, but you can install it using the instructions from the What you will need section.

    from requests import get
import json
from pprint import pprint

The requests module allows you to fetch web pages from the World Wide Web. The json module allows you to easily read JSON data (which is a way of organising data into dictionaries). The pprint module is short for pretty-print, and just makes presenting text a little clearer.

  • The next thing to do is to save that URL you used earlier as a variable:

    url = 'https://apex.oracle.com/pls/apex/raspberrypi/weatherstation/getallstations'

  • Using get from the requests module you can now fetch the data, and translate it into Python dictionaries using the json module:

    stations = get(url).json()['items']

  • Save and run your code.

  • Type stations into the Python shell to have a look at the data.

look at the data in idle

  • It still looks pretty ugly. Try typing pprint(stations) and see what happens. You should see a huge list of Weather Stations dictionaries. Each dictionary should look something like this:

    {'weather_stn_id': 1648902,
 'weather_stn_lat': 52.197834,
 'weather_stn_long': 0.125366,
 'weather_stn_name': 'ACRG_ROOF'}]

What you’re seeing is:

  • weather_stn_id – the unique ID of the station (weather_stn_id)
  • its location in the world (you will learn about this later in the project)
    • weather_stn_lat – the latitude
    • weather_stn_long – the longitude
  • weather_stn_name – the name of the Weather Station.

For the next part, you’re going to need to pick a Weather Station to fetch the weather from.

  • Scroll up and down the list and pick a weather_stn_id that you’d like to have a look at.
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