Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
When an opponent's monster declares an attack: You can Special Summon this card from your hand. Your opponent's monsters cannot attack any monsters, except this one.
--ジェントルーパー
--Gentlemander
local s,id=GetID()
function s.initial_effect(c)
	--spsummon
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_SPECIAL_SUMMON)
	e1:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_TRIGGER_O)
	e1:SetCode(EVENT_ATTACK_ANNOUNCE)
	e1:SetRange(LOCATION_HAND)
	e1:SetCondition(s.condition)
	e1:SetTarget(s.target)
	e1:SetOperation(s.operation)
	c:RegisterEffect(e1)
	--atk limit
	local e2=Effect.CreateEffect(c)
	e2:SetType(EFFECT_TYPE_FIELD)
	e2:SetCode(EFFECT_CANNOT_SELECT_BATTLE_TARGET)
	e2:SetRange(LOCATION_MZONE)
	e2:SetTargetRange(0,LOCATION_MZONE)
	e2:SetValue(s.atlimit)
	c:RegisterEffect(e2)
end
function s.condition(e,tp,eg,ep,ev,re,r,rp)
	return Duel.GetAttacker():GetControler()~=tp
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk)
	local c=e:GetHandler()
	if chk==0 then return Duel.GetLocationCount(tp,LOCATION_MZONE)>0
		and c:IsCanBeSpecialSummoned(e,0,tp,false,false) end
	Duel.SetOperationInfo(0,CATEGORY_SPECIAL_SUMMON,c,1,0,0)
end
function s.operation(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	if not c:IsRelateToEffect(e) then return end
	Duel.SpecialSummon(c,0,tp,tp,false,false,POS_FACEUP)
end
function s.atlimit(e,c)
	return c~=e:GetHandler()
end