Pandas dataframe to json list format

Question

I have large pandas tabular dataframe to convert into JSON. The standard .to_json() functions does not make a compact format for JSON. How to get JSON output forma like this

Answer 1

You can use to_dict and json (and add the index as extra column if required via assign):

import json

df = pd.DataFrame({"col1": [250, 1, 3],
                   "col2": [250, 1, 3]})

json_dict = df.assign(index=df.index).to_dict(orient="list")
print(json.dumps(json_dict))

>>> '{"index": [0, 1, 2], "col1": [250, 1, 3], "col2": [250, 1, 3]}'