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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 angle(v1,v2, cos=False):
 """ Find the angle between two vectors. :param cos: If True, the cosine of the angle will be returned. False by default. """

    n = (norm(v1)*norm(v2))
    _ = dot(v1,v2)/n
    return _ if cos else N.arccos(_)