def _get_coeff_exp(expr, x):
    """
    When expr is known to be of the form c*x**b, with c and/or b possibly 1,
    return c, b.

    >>> from sympy.abc import x, a, b
    >>> from sympy.integrals.meijerint import _get_coeff_exp
    >>> _get_coeff_exp(a*x**b, x)
    (a, b)
    >>> _get_coeff_exp(x, x)
    (1, 1)
    >>> _get_coeff_exp(2*x, x)
    (2, 1)
    >>> _get_coeff_exp(x**3, x)
    (1, 3)
    """
    from sympy import powsimp
    (c, m) = expand_power_base(powsimp(expr)).as_coeff_mul(x)
    if not m:
        return c, S(0)
    [m] = m
    if m.is_Pow:
        if m.base != x:
            raise _CoeffExpValueError('expr not of form a*x**b')
        return c, m.exp
    elif m == x:
        return c, S(1)
    else:
        raise _CoeffExpValueError('expr not of form a*x**b: %s' % expr)
dataset/ETHPy150Open sympy/sympy/sympy/integrals/meijerint.py/_get_coeff_exp/original