How do conver and I access the properties of an array of objects python saved as string

Question

I have the following array structure, which I consume from a .csv file

0,Done,"[{'id': '7-84-1811', 'idType': 'CIP', 'suscriptionId': '89877485'}]"
0,Done,"[{'id': '1-232-42', 'idType': 'IO', 'suscriptionId': '23532r32'}]"
0,Done,"[{'id': '2323p23', 'idType': 'LP', 'suscriptionId': 'e32e23dw'}]"
0,Done,"[{'id': 'AU23242', 'idType': 'LL', 'suscriptionId': 'dede143234'}]"

To be able to handle it with pandas, I created its respective columns, but I only need to access the "id" and "idType" properties.

My code

from pandas.io.json import json_normalize
import pandas as pd

path = 'path_file'
df_fet = pd.read_csv(path, names=['error', 'resul', 'fields'])
df_work = df_fet[['fields'][0]['id', 'idType']]
print(df_work.head())

Retorn error TypeError: string indices must be integers

desired output

             id,  idType
0.   '7-84-1811', 'CIP'
1.   '1-232-42',  'IO'
...

https://stackoverflow.com/a/1894296/2834978 – LMC Oct 17 '22 at 17:07 — LMC, Oct 17 '22 at 17:07
That is not "an array of objects". That is a string. – juanpa.arrivillaga Oct 17 '22 at 17:17 — juanpa.arrivillaga, Oct 17 '22 at 17:17

score 0 · Accepted Answer · answered Oct 17 '22 at 17:35

Here's a way to achieve the desired output

import pandas as pd

path = 'filepath'
df = pd.read_csv(path, names=['error', 'resul', 'fields'])
df["fields"] = df["fields"].fillna("[]").apply(lambda x: eval(x))
arr = []
for row in df["fields"]:
    arr.append([row[0]["id"], row[0]["idType"]])
new = pd.DataFrame(arr, columns=["id", "idType"])
print(new)

Output:

Using eval() function python interprets the argument as a python expression thus the string is interpreted as a list itself

How do conver and I access the properties of an array of objects python saved as string

1 Answers1