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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 size_from_name(size, sizes):
 """Return a size from a list of sizes."""


    by_name = [s for s in sizes if s.name == size]
    if len(by_name) > 1:
        raise Exception('more than one image named %s exists' % size)
    return by_name[0]