嵌套哈希中相同键的求和键值对

Question

我有下面的散列-

array = [{:Air_Duct_Cleaning=>{:impressions=>92, :clicks=>2, :conversions=>0}, :Carpet_Cleaning=>{:impressions=>297, :clicks=>0, :conversions=>0}, :Brand_Terms=>{:impressions=>273, :clicks=>9, :conversions=>1}}, {:Brand_Terms=>{:impressions=>275, :clicks=>3, :conversions=>0}}, {:Air_Duct_Cleaning=>{:impressions=>51, :clicks=>1, :conversions=>0}, :Carpet_Cleaning=>{:impressions=>225, :clicks=>0, :conversions=>0}, :Brand_Terms=>{:impressions=>326, :clicks=>12, :conversions=>2}}]

我试图把相同键的键值对和起来。例如-

air_duct = array.map {|m| m[:Air_Duct_Cleaning]}.compact
=> [{:impressions=>92, :clicks=>2, :conversions=>0}, {:impressions=>51, :clicks=>1, :conversions=>0}]

air_duct_total = air_duct.inject{|x,y| x.merge(y){|a,b,c| b + c}}
=> {:impressions=>143, :clicks=>3, :conversions=>0}

但是，我需要在不知道第一级哈希键(不会知道:Air_Duct_Cleaning的键)的情况下这样做。我试图在数组中迭代，运行如下

key_groups = array.map {|m| m.map {|key, value| key}}

希望这能将每个键定位在:Air_Duct_Cleaning的位置上，我会得到这样的信息

[{:Air_Duct_Cleaning =>{:impressions=>92, :clicks=>2, :conversions=>0}, {:impressions=>51, :clicks=>1, :conversions=>0}, {:Carpet_Cleaning => {:impressions=>297, :clicks=>0, :conversions=>0}, {:impressions=>225, :clicks=>0, :conversions=>0}, {:Brand_Terms => {:impressions=>273, :clicks=>9, :conversions=>1}, {:impressions=>275, :clicks=>3, :conversions=>0}, {:impressions=>326, :clicks=>12, :conversions=>2}]

所以我可以用这样的方法

totals = key_groups.map {|m| m.inject{|x,y| x.merge(y){|a,b,c| b + c}}}

最终以

[{:Air_Duct_Cleaning => {:impressions=>143, :clicks=>3, :conversions=>0}, {:Carpet_Cleaning => {:impressions=>522, :clicks=>0, :conversions=>0}, {:Brand_Terms => {:impressions=>874, :clicks=>24, :conversions=>3}] 

Answer 1

这将产生所需的输出，而无需使用输入数组的显式键：

array = [
  { Air_Duct_Cleaning: { impressions: 92, clicks: 2, conversions: 0 }, Carpet_Cleaning: { impressions: 297, clicks: 0, conversions: 0 }, Brand_Terms: { impressions: 273, clicks: 9, conversions: 1 }},
  { Brand_Terms: { impressions: 275, clicks: 3, conversions: 0 }},
  { Air_Duct_Cleaning: { impressions: 51, clicks: 1, conversions: 0 }, Carpet_Cleaning: { impressions: 225, clicks: 0, conversions: 0 }, Brand_Terms: { impressions: 326, clicks: 12, conversions: 2 }},
]

result = array.reduce({}) do |o, hash|
  o.merge(hash) { |_, v1, v2| v1.merge(v2) { |_, vv1, vv2| vv1 + vv2 } }
end

p result
# {
#   :Air_Duct_Cleaning=>{:impressions=>143, :clicks=>3, :conversions=>0}, 
#   :Carpet_Cleaning=>{:impressions=>522, :clicks=>0, :conversions=>0}, 
#   :Brand_Terms=>{:impressions=>874, :clicks=>24, :conversions=>3}
# }