def lognstat(mu, sigma):
    """Calculate the mean of and variance of the lognormal distribution given
    the mean (`mu`) and standard deviation (`sigma`), of the associated normal 
    distribution."""
m = np.exp(mu + sigma ** 2 / 2.0)
v = np.exp(2 * mu + sigma ** 2) * (np.exp(sigma ** 2) - 1)
return m, v
Is there a Python method to calculate lognormal mean and variance?