字典的向量化索引 [英] Vectorized indexing for a dictionary

问题描述

我想在Julia中找到一种简洁的语法，以向量化的方式索引字典.在R中，我将执行以下操作:

I would like to find a succinct syntax in Julia for indexing a dictionary in a vectorized manner. In R, I would do the following:

dict <- c("a" = 1, "b" = 2)
keys <- c("a", "a", "b", "b", "a")
dict[keys]

在朱莉娅中，如果我有这样的dict和keys，

In Julia, if I have a dict and keys like this,

dict = Dict(:a => 1, :b => 2)
keys = [:a, :a, :b, :b, :a]

然后我可以使用列表理解来达到预期的结果:

then I can achieve the desired result using a list comprehension:

julia> [dict[key] for key in keys]
5-element Array{Int64,1}:
 1
 1
 2
 2
 1

是否有更简洁的矢量化语法，类似于R语法?

Is there a more succinct vectorized syntax, similar to the R syntax?

推荐答案

getindex.(Ref(dict), keys)

您可以将其包装在Ref中，因此无需[].

You can wrap it in Ref so you don't need to [] it.

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