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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def field_lookup(obj, field_path):
 """ Lookup django model field in similar way of django query lookup. Args: obj (instance):
 Django Model instance field_path (str):
 '__' separated field path Example: """

    if hasattr(obj, 'iterator'):
        return (field_lookup(x, field_path) for x in obj.iterator())
    elif isinstance(obj, Iterable):
        return (field_lookup(x, field_path) for x in iter(obj))
    # split the path
    field_path = field_path.split('__', 1)
    if len(field_path) == 1:
        return getattr(obj, field_path[0], None)
    return field_lookup(field_lookup(obj, field_path[0]), field_path[1])