code: def do_bestfit(self):
          
          self.check_important_variables()
          x = np.array(self.args["x"])
          y = np.array(self.args["y"])
          p = self.args.get("params", np.ones(self.args["num_vars"]))
          self.fit_args, self.cov = opt.curve_fit(self.args["func"], x, y, p)
          return self.fit_args
docs: Do bestfit