def _check_values(self, X):
        low_var = (X.var(0) < 10e-5)
        if low_var.any():
            cols = str(list(X.columns[low_var]))
            print("Warning: column(s) %s have very low variance.\
 This may harm convergence." % cols)
dataset/ETHPy150Open CamDavidsonPilon/lifelines/lifelines/fitters/coxph_fitter.py/CoxPHFitter._check_values/original