Acquire and aggregate/merge data for multiple sets of parameters

[earthobservations]

Acquire and aggregate/merge data for multiple sets of parameters

[gutzbenj]

As already suggested, I'd like to implement a reshape of the data according to [1]. This would simplify filtering as well as aggregating (especially also over time ranges like days, weeks etc). In order for it to work in the client version I guess only minimal changes have to be applied.

[1] https://vita.had.co.nz/papers/tidy-data.pdf

[gutzbenj]

With #118 we will now be able to extend the DWDStationRequest with further parameters, as the resulting columns will always be the same and we can simply extend the DataFrame with other parameters. In opposition to the result you were suggesting I'd rather prefer something like:

{
    "meta" : {
        "station_id": 2667,
        "datetime": 2020060115,
    },
    "data" : {
        "air_temperature": {
            "air_temperature_200": {
                "value": 27.0,
                "quality": 1
            },
        },
        "more_precip": {
            "relative_humidity_200": {
                "value": 26.0,
                "quality": 1
            },
            "precipitation_fallen": {
                "value": 0,
                "quality": 1
            },
            "precipitation_form": {
                "value": null,
                "quality": 1
            },
            "precipitation_height": {
                "value": 0.0,
                "quality": 1
            },
        },
        "pressure": {
            "pressure_msl": {
                "value": 1019.0,
                "quality": 1
            },
            "pressure_station": {
                "value": 1007.6,
                "quality": 1
            }
        }
    }
}

Ofcourse this is not as tiny and compact as you suggested, but this is more clear concerning the included parameters and the qualities of every value which otherwise would have to be interpreted by the user for cases where there are two qualities.

[gutzbenj]

I realized we may as well include additional station information to create an almost complete set.

[gutzbenj]

#121 added the option to request multiple parameters. The data will still be combined per station.