expr.py 文件源码

def compute_leading_term(self, x, logx=None):
        """
        as_leading_term is only allowed for results of .series()
        This is a wrapper to compute a series first.
        """
        from sympy import Dummy, log
        from sympy.series.gruntz import calculate_series

        if self.removeO() == 0:
            return self

        if logx is None:
            d = Dummy('logx')
            s = calculate_series(self, x, d).subs(d, log(x))
        else:
            s = calculate_series(self, x, logx)

        return s.as_leading_term(x)