<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def prepare_object(obj, using="default"):
 """ Returns a Python dictionary representation of the given object, expected to be a Model object with an associated SearchIndex. The optional argument `using` specifies the backend to use from the Haystack connections list. """

    model = obj.__class__
    unified_index = connections[using].get_unified_index()
    index = unified_index.get_index(model)
    prepped_data = index.full_prepare(obj)
    final_data = {}
    for key, value in prepped_data.items():
        final_data[key] = connections[using].get_backend()._from_python(value)
    return final_data