stats
DescrStatsW.
var_ddof
variance of data given ddof
ddof : int, float
degrees of freedom correction, independent of attribute ddof
var : float, ndarray
variance with denominator sum_weights - ddof
sum_weights - ddof
statsmodels.stats.weightstats.DescrStatsW.var
statsmodels.stats.weightstats.DescrStatsW.zconfint_mean