From
http://docs.scipy.org/doc/scipy/reference/tutorial/stats.html
As an exercise, we can calculate our ttest also directly without using
the provided function, which should give us the same answer, and so it
does:
tt = (sm-m)/np.sqrt(sv/float(n)) # t-statistic for mean
pval = stats.t.sf(np.abs(tt), n-1)*2 # two-sided pvalue = Prob(abs(t)>tt)
print 't-statistic = %6.3f pvalue = %6.4f' % (tt, pval)
t-statistic = 0.391 pvalue = 0.6955