Python, list of nested repeated keys

I would like to process this json data in python:

{"data":
   [{"CU":"AGLD","CO": [{"chain":"ERC20"}],                 "fn":"Adventure Gold"}, 
    {"CU":"ACH","CO":  [{"chain":"ERC20"},    {"chain":"BEP20"}],   "fn":"Alchemy"}]}
    

I would like to get the value of all “chain”s. For example like this:

CU  chains:
AGLD    ERC20
ACH     ERC20
ACH     BEP20

I tried with a for loop, but (in the case of several “chain”s) it returns only the last value of “chain” for example ACH BEP20. Does not return ACH ERC20.

Answer

You said you used for-loop but you need neested for-loops – like this:

data = {"data": [
    {"CU":"AGLD", "CO": [{"chain": "ERC20"}],                    "fn":"Adventure Gold"}, 
    {"CU":"ACH",  "CO": [{"chain": "ERC20"}, {"chain":"BEP20"}], "fn":"Alchemy"}
]}

for item in data['data']:
    for subitem in item['CO']:
        print(item['CU'], subitem['chain'])

Result:

AGLD ERC20
ACH ERC20
ACH BEP20    

---

BTW:

You didn’t show how you keep it but if you keep in dictionary then you need list to keep all values result[key] = [value1, value2]. If you will assing result[key] = value then you get only last item.