Parsing openweathermap.org

[matt42]

Hi there,
new MP user with an esp32.
MicroPython v1.12-388-g388d419ba

I am trying to get info from api.openweathermap.org API and parse it to get some individual values. Here is my code:

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import urequests, ujson
def url():
    r = urequests.get("https://api.openweathermap.org/data/2.5/onecall?<snipped>")
    ud = r.text
    raw = ujson.loads(ud)
    t = raw.get('current').get('temp')
    w = raw.get('current').get('weather')
    print(t)
    print(w)
url()

The openweathermap URL provides data like this:

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{"timezone":"Australia/Melbourne","current":{"dt":1587788262,"sunrise":1587761706,"sunset":1587800335,"temp":20.58,"feels_like":18.94,"pressure":1015,"humidity":61,"dew_point":12.8,"uvi":3.5,"clouds":87,"wind_speed":3.58,"wind_deg":57,"wind_gust":7.15,"weather":[{"id":804,"main":"Clouds","description":"overcast clouds","icon":"04d"}]},"hourly": <snipped>

The output of my program is this:

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20.34
[{'id': 804, 'icon': '04d', 'main': 'Clouds', 'description': 'overcast clouds'}]

How do I get the result of "description"? It is embedded between "[ ]" and the normal ".get" does not work. It seems to be a dictionary trapped in a list and i'm not sure how to handle it.

thanks in advance,

Matt

[jimmo]

It seems to be a dictionary trapped in a list and i'm not sure how to handle it.

Yep, it's exactly that.

So

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w = raw.get('current').get('weather')

w is a list of dictionaries. So w[0] is the first element of the list, then w[0].get('description') will be what you want. (You can use len(w) to see if there are any entries, or even just "if w:").

I looked briefly at their docs, it's not clear if there's always at least one entry in the "weather" list (i.e. can you always assume that w[0] exists). Also it seems possible that there could be more than one.

[matt42]

Thanks Jimmo, easy when you know how. Your explanation makes alot of sense and now I can access the data I need

cheers
Matt