how to take first column of a json

import json

def convert(input_data):  
    if isinstance(input_data, dict):
        return {key: convert(value) for key, value in input_data.items()}
    elif isinstance(input_data, list):
        return [convert(element) for element in input_data]
    elif isinstance(input_data, str):
        return input_data.encode('ascii', 'ignore')
    else:
        return input_data

raw_data = '{"1": "one", "2": "two", "3": "three"}'
json_data = json.loads(raw_data)
print(convert(json_data))