How to convert pandas dataframe to specific json format

Question

I have been looking at different methods to export pandas dataframes into json files but I am not sure how to include other string 'constants' into the JSON.

The purpose is to spit out a JSON file that can be read by chart.js .

The format of the pandas dataframe for the example is:

    month   order   visit   frequency
0   1월      171     2042    8.4
1   2월      72      475     15.2
2   3월      68      405     16.8
3   4월      84      991     8.5
4   5월      96      684     14.0
5   6월      58      576     10.1
6   7월      78      671     11.6
7   8월      67      576     11.6
8   9월      140     1168    12.0
9   10월     124     837     14.8

The format of the JSON required file is:

{
  "labels": [
    "1월", "2월", "3월", "4월", "5월", "6월", "7월", "8월", "9월", "10월"
  ],
  "datasets": [
    {
      "label": "order",
      "data": [
        171, 72, 68, 84, 96, 58, 78, 67, 140, 124
      ]
    },
    {
      "label": "visit",
      "data": [
        2042, 475, 405, 991, 684, 576, 671, 576, 1168, 837
      ]
    },
    {
      "label": "frequency",
      "data": [
        8.4, 15.2, 16.8, 8.5, 14, 10.1, 11.6, 11.6, 12, 14.8
      ]
    }
  ]
}

i can export the pandas file as JSON using the inbuilt functions of pandas but i do not know how to separate the vectors and add the constant values seen above.

My purpose is a json format which can be used in chart.js

Answer 1

You could solve it like so:

df = df.set_index('month')
out = {'labels': df.index.tolist(), 'datasets': []}
for col in df.columns:
    out['datasets'].append({
        'label': col,
        'data': df[col].values.tolist()
    })