在Julia中通過對相同的鍵值進行求和來添加詞典

Question

我在朱莉婭有兩個詞典a1和a2。

a1 = {"A"=>1, "B"=>2} 
a2 = {"A"=>4, "B"=>1, "C"=>3} 

我想結合它來得到這個。

final={"A"=>5, "B"=>3, "C"=>3} 

在Python中，我將字典轉換爲收集計數器並將它們組合在一起。

Answer 1

看看DataStructures.jl計數器。

julia> using DataStructures: counter 

julia> a1 = Dict{ASCIIString, Int64}("A"=>1, "B"=>2) 
Dict{ASCIIString,Int64} with 2 entries: 
    "B" => 2 
    "A" => 1 

julia> a2 = Dict{ASCIIString, Int64}("A"=>4, "B"=>1, "C"=>3) 
Dict{ASCIIString,Int64} with 3 entries: 
    "B" => 1 
    "A" => 4 
    "C" => 3 

julia> merge(counter(a1), counter(a2)).map 
Dict{ASCIIString,Int64} with 3 entries: 
    "B" => 3 
    "A" => 5 
    "C" => 3 

Answer 2

對於任何人在這個現在正在尋找，counter不再是必要的 - 使用merge(+, a1, a2)。

julia> a1 = Dict("A"=>1, "B"=>2) 
Dict{String,Int64} with 2 entries: 
    "B" => 2 
    "A" => 1 
julia> a2 = Dict("A"=>4, "B"=>1, "C"=>3) 
Dict{String,Int64} with 3 entries: 
    "B" => 1 
    "A" => 4 
    "C" => 3 
julia> merge(+, a1, a2) 
Dict{String,Int64} with 3 entries: 
    "B" => 3 
    "A" => 5 
    "C" => 3