human
I wrote the below code

    from sympy import re, Max, Min, count_ops
    s = _dummy('s', 'mellin-transform', f)
    F = integrator(((x ** (s - 1)) * f), x)
    if (not F.has(Integral)):
        return (_simplify(F.subs(s, s_), simplify), ((- oo), oo), True)
    if (not F.is_Piecewise):
        raise IntegralTransformError('Mellin', f, 'could    not    compute    integral')
    (F, cond) = F.args[0]
    if F.has(Integral):
        raise IntegralTransformError('Mellin', f, 'integral    in    unexpected    form')
    def process_conds(cond):
        '\n                                Turn    ``cond``    into    a    strip    (a,    b),    and    auxiliary    conditions.\n                                '
        a = (- oo)
        b = oo
        aux = True
        conds = conjuncts(to_cnf(cond))
        t = Dummy('t', real=True)
        for c in conds:
            a_ = oo
            b_ = (- oo)
            aux_ = []
            for d in disjuncts(c):
                d_ = d.replace(re, (lambda x: x.as_real_imag()[0])).subs(re(s), t)
                if ((not d.is_Relational) or (d.rel_op in ('==', '!=')) or d_.has(s) or (not d_.has(t))):
                    aux_ += [d]
                    continue
                soln = _solve_inequality(d_, t)
                if ((not soln.is_Relational) or (soln.rel_op in ('==', '!='))):
                    aux_ += [d]
                    continue
                if (soln.lts == t):
                    b_ = Max(soln.gts, b_)
                else:
                    a_ = Min(soln.lts, a_)
            if ((a_ != oo) and (a_ != b)):
                a = Max(a_, a)
            elif ((b_ != (- oo)) and (b_ != a)):
                b = Min(b_, b)
            else:
                aux = And(aux, Or(*aux_))
        return (a, b, aux)
    conds = [process_conds(c) for c in disjuncts(cond)]
    conds = [x for x in conds if (x[2] != False)]
    conds.sort(key=(lambda x: ((x[0] - x[1]), count_ops(x[2]))))
    if (not conds):
        raise IntegralTransformError('Mellin', f, 'no    convergence    found')
    (a,...

What's a good function header?
assistant
#Here is Python code to compute    integral')
.

@_noconds
def _mellin_transform(f, x, s_, integrator=_default_integrator, simplify=True):