Have a dict in double quoted string trying to convert it into normal dict using json.loads but getting json decode error

Trying to get the dictionary from string using json.loads but getting Exception JSONDecodeError: Expecting property name enclosed in double quotes: line 1 column 2 (char 1).

Below is the exact string value in contract_details for anyone to try:

contract_details = "{'instrumentToken': 17098, 'instrumentName': 'BANKNIFTY', 'name': nan, 'lastPrice': 333.05, 'expiry': '07OCT21', 'strike': 37800.0, 'tickSize': 0.05, 'lotSize': 25, 'instrumentType': 'OI', 'segment': 'FO', 'exchange': 'NSE', 'isin': nan, 'multiplier': 1, 'exchangeToken': 40728, 'optionType': 'PE'}"

contract_details = current_order["contract_details"]
contract_details = json.loads(contract_details)

>Solution :

As the error message Expecting property name enclosed in double quotes suggests , json expects strings to have double quotes around the values inside the string. You can change the source if possible or replace the single quotes with double quotes using replace("'", '"') on contract_details, you also need to replace 'nan' with 'NaN'

json.loads(contract_details.replace("'", '"').replace('nan', 'NaN'))