Pandas to D3. Serializing dataframes to JSON

Question

I have a DataFrame with the following columns and no duplicates:

[\'region\', \'type\', \'name\', \'value\']

that can be seen as a hierarchy as

Answer 1

Something along these lines might get you there.

from collections import defaultdict

tree = lambda: defaultdict(tree)  # a recursive defaultdict
d = tree()
for _, (region, type, name, value) in df.iterrows():
    d['children'][region]['name'] = region
    ...

json.dumps(d)

A vectorized solution would be better, and maybe something that takes advantage of the speed of groupby, but I can't think of such a solution.

Also take a look at df.groupby(...).groups, which return a dict.

See also this answer.