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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 EvalPoissonPmf(k, lam):
 """Computes the Poisson PMF. k: number of events lam: parameter lambda in events per unit time returns: float probability """

    # don't use the scipy function (yet).  for lam=0 it returns NaN;
    # should be 0.0
    # return scipy.stats.poisson.pmf(k, lam)

    return lam ** k * math.exp(-lam) / math.factorial(k)