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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 select_models(clas,pool_or_cursor,**kwargs):
    "returns generator yielding instances of the class"
    if 'columns' in kwargs: raise ValueError("don't pass 'columns' to select_models")
    return (set_options(pool_or_cursor,clas(*row)) for row in clas.select(pool_or_cursor,**kwargs))