def rs_hadamard_exp(p1, inverse=False):
    """
    Return ``sum f_i/i!*x**i`` from ``sum f_i*x**i``,
    where ``x`` is the first variable.

    If ``invers=True`` return ``sum f_i*i!*x**i``

    Examples
    ========

    >>> from sympy.polys.domains import QQ
    >>> from sympy.polys.rings import ring
    >>> from sympy.polys.ring_series import rs_hadamard_exp
    >>> R, x = ring('x', QQ)
    >>> p = 1 + x + x**2 + x**3
    >>> rs_hadamard_exp(p)
    1/6*x**3 + 1/2*x**2 + x + 1
    """
    R = p1.ring
    if R.domain != QQ:
        raise NotImplementedError
    p = R.zero
    if not inverse:
        for exp1, v1 in p1.items():
            p[exp1] = int(ifac(exp1[0]))/v1
    else:
        for exp1, v1 in p1.items():
            p[exp1] = v1*int(ifac(exp1[0]))
    return p
dataset/ETHPy150Open sympy/sympy/sympy/polys/ring_series.py/rs_hadamard_exp/swapped operands of `/`