non-null values intercept non-null values dtypesfloat ( in [ ]model beta['msft'plot(figure - one-year correlation of apple with microsoft figure - one-year beta (ols regression coefficientof apple to microsoft pandas' ols function implements static and dynamic (expanding or rolling windowleast squares regressions for more sophisticated statistical and econometrics modelssee the statsmodels project (more example applications www it-ebooks info