# scipy.stats.poisson.interval - what confidence interval

What kind of confidence interval does scipy.stats.poisson.interval return? Is it normal approximation? I went on GitHub, but could not look it up in the code. How can I look it up in the code?

It's not a confidence interval. The scipy.stats.poisson object is a subclass of the scipy.stats.rv_discrete class (i.e., its "parent" class). The parent class defines the .interval method here: http://docs.scipy.org/doc/scipy/reference/generated/scipy.stats.rv_discrete.interval.html#scipy.stats.rv_discrete.interval
You'll notice that both this description on the one for the poisson both say that it is an interval that captures a alpha percent of the distribution. Hence, this is really not a confidence interval, but a probability interval (it contains alpha percent of the total probability).