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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 ssa(scatterer, h_pol=True):
 """Single-scattering albedo for the current setup, with polarization. Args: scatterer: a Scatterer instance. h_pol: If True (default), use horizontal polarization. If False, use vertical polarization. Returns: The single-scattering albedo. """


    ext_xs = ext_xsect(scatterer, h_pol=h_pol)
    return sca_xsect(scatterer, h_pol=h_pol)/ext_xs if ext_xs > 0.0 else 0.0