Pandas - expand nested json array within column in dataframe

Question

I have a json data (coming from mongodb) containing thousands of records (so an array/list of json object) with a structure like the below one for each object:

{         


        

Answer 1

I propose an interesting answer I think using pandas.json_normalize.
I use it to expand the nested json -- maybe there is a better way, but you definitively should consider using this feature. Then you have just to rename the columns as you want.

import io
from pandas import json_normalize

# Loading the json string into a structure
json_dict = json.load(io.StringIO(json_str))

df = pd.concat([pd.DataFrame(json_dict), 
                json_normalize(json_dict['nested_array_to_expand'])], 
                axis=1).drop('nested_array_to_expand', 1)