julia - 如何使用 Julia 将两个字典合并到一个表达式中？

Question

我定义了两个单独的字典。我想知道是否有一种优雅的、单一的表达方式可以将这两个字典合并为一个？

Answer 1

是的，使用merge()函数。这是一个简单的例子:

julia> a = Dict("One" => 1.0, "Two" => 2.0)
Dict{String,Float64} with 2 entries:
  "One" => 1.0
  "Two" => 2.0

julia> b = Dict("Three" => 3, "Four" => 4)
Dict{String,Int64} with 2 entries:
  "Three" => 3
  "Four"  => 4

julia> c = merge(a, b)
Dict{String,Float64} with 4 entries:
  "One"   => 1.0
  "Two"   => 2.0
  "Three" => 3.0
  "Four"  => 4.0

请参阅 Julia 文档 here有关与 merge() 相关的更多示例和功能。 merge 函数创建一个新的、单独的字典并返回它。还有一个变异 merge! 函数可以修改其第一个参数:

julia> merge!(a, b)
Dict{String,Float64} with 4 entries:
  "One"   => 1.0
  "Two"   => 2.0
  "Three" => 3.0
  "Four"  => 4.0

julia> a
Dict{String,Float64} with 4 entries:
  "One"   => 1.0
  "Two"   => 2.0
  "Three" => 3.0
  "Four"  => 4.0

请注意，merge! 返回合并后的数组，该数组是修改后的原始字典a。