Julia-在@variable和@constraint表达式中按名称访问Dict值

我想知道是否可以通过以下表达式中的名称访问Dict值：

@objective(
    premex,
    Min,
    sum((u["cap"] - PRODAMOUNT[op, u, t]) * u["util_cost1"]
        for op in _ORDER_PRODUCTS, u in UNITS, t in TIME))

_订购产品：

Dict{String,Dict{String,Any}}("o18-p25" => Dict("order" => "o18","value" => 3000.0f0,"product" => "p25"),"o18-p36" => Dict("order" => "o18","value" => 63.0f0,"product" => "p36"),"o23-p39" => Dict("order" => "o23","value" => 204.75f0,"product" => "p39"),"o16-p32" => Dict("order" => "o16","value" => 336.0f0,"product" => "p32"),"o22-p37" => Dict("order" => "o22","value" => 50.0f0,"product" => "p37"),"o1-p5" => Dict("order" => "o1","value" => 60.0f0,"product" => "p5"),"o11-p28" => Dict("order" => "o11","value" =....

单位：

UNITS = Dict(["CINTAS" => Dict(["cap" => 1000, "mincap" => 50, "dcap" => 24830, "util_cost1" => 1000, "maxprodr" => 24830]), "BUHLER1" => Dict(["cap" => 1500, "mincap" => 60, "dcap" => 37245, "util_cost1" => 1000, "maxprodr" => 37245]), ...

当我运行此命令时，出现了一个错误：

错误：LoadError:MethodError:没有与getindex匹配的方法（：：Pair{String，Dict{String，Integer}，：：String）

当我把u[“cap”]替换成一个数字时，它就起作用了。

我自己找到了答案（…）：

有三个因素需要注意：

无法使用dictionary对象索引变量，因此它必须是Int或String

这是迭代Dict:for（key1，op）in_ORDER_产品的方法

这是只获取索引变量的键的方法：opin键（_ORDER_PRODUCTS）

---

如果你解决了它，你应该接受你自己的答案。@MatějRačinský谢谢，我会立即接受它，但正如你已经知道的那样=这是不可能的，因此我把它留到以后，正如你已经知道的那样=在我忘记它之后：）

    @variable(premex, PRODAMOUNT[op in keys(_ORDER_PRODUCTS), u in keys(UNITS), t in TIME])

    @objective(
        premex,
        Min,
        sum((u["cap"] - PRODAMOUNT[key1, key2, t]) * u["util_cost1"]
            for (key1, op) in _ORDER_PRODUCTS, (key2, u) in UNITS, t in TIME
                ))