Jsonize Pandas Complex Times Series From Numpy Vector-CodePudding

I have this numpy 2x10 vector

data = np.ones((10,2)

I would like to make a JSON string with this format:

[{
 "times":"2022-11-10 00:00:00",
 "values": {
    "first": <values of the 1st row>,
    "second": <values of the 2nd row>,
 }
}
]

What I have done up to now:

dft = pd.DataFrame(data,columns=["first","second"],
                   index=pd.date_range(start_date, periods=len(data), freq=f"15T")
            )
            dft.reset_index(inplace=True)
            dft = dft.rename(columns={'index': 'times'})
            out = dft.to_json(orient='records')

And what I get is:

[{"times":1357041600000,"first":0.0,"second":0.0},{"times":1357042500000,"first":0.0,"second":0.0},{"times":1357043400000,"first":0.0,"second":0.0},{"times":1357044300000,"first":0.0,"second":0.0},{"times":1357045200000,"first":0.0,"second":0.0},{"times":1357046100000,"first":0.0,"second":0.0},{"times":1357047000000,"first":0.0,"second":0.0},{"times":1357047900000,"first":0.0,"second":0.0},{"times":1357048800000,"first":0.0,"second":0.0},{"times":1357049700000,"first":0.0,"second":0.0}]

How can introduce 1) the "values" field as per specification and 2) cast the column times to datetime? Regards!

CodePudding user response：

No need for a DataFrame here, a simple list comprehension will be easier:

import json

start_date = '2022-11-10'
dates = pd.date_range(start_date, periods=len(data), freq=f"15T")

out = [json.dumps({"times":"2022-11-10 00:00:00", 
                   "values": {"first": a, "second": b}}
                   ) for time, (a, b) in zip(dates, data)
       ]

Output:

['{"times": "2022-11-10 00:00:00", "values": {"first": 1.0, "second": 1.0}}',
 '{"times": "2022-11-10 00:00:00", "values": {"first": 1.0, "second": 1.0}}',
 '{"times": "2022-11-10 00:00:00", "values": {"first": 1.0, "second": 1.0}}',
 '{"times": "2022-11-10 00:00:00", "values": {"first": 1.0, "second": 1.0}}',
 '{"times": "2022-11-10 00:00:00", "values": {"first": 1.0, "second": 1.0}}',
 '{"times": "2022-11-10 00:00:00", "values": {"first": 1.0, "second": 1.0}}',
 '{"times": "2022-11-10 00:00:00", "values": {"first": 1.0, "second": 1.0}}',
 '{"times": "2022-11-10 00:00:00", "values": {"first": 1.0, "second": 1.0}}',
 '{"times": "2022-11-10 00:00:00", "values": {"first": 1.0, "second": 1.0}}',
 '{"times": "2022-11-10 00:00:00", "values": {"first": 1.0, "second": 1.0}}']