按键对嵌套哈希中的项进行排序

Question

I have a nested hash with unsorted keys:

given =  {
  "lorem" => {
     :AA => "foo",
     :GR => "foo",
     :BB => "foo"
  },
  "ipsum" => {
    :ZZ => "foo",
    :GR => "foo",
  }
}

What I'm trying to accomplish is a hash with sorted keys:

goal =  {
  "ipsum" => {
    :GR => "foo",
    :ZZ => "foo"
  },
  "lorem" => {
     :AA => "foo",
     :BB => "foo",
     :GR => "foo"
  }
}

I have experimented with .each method and sort_by

given.each { |topic| topic[:key].sort_by { |k, v| k } }

But I'm getting an error message: TypeError: no implicit conversion of Symbol into Integer

Any help is greatly appreciated!

PS: I noticed with gem pry the output is already sorted. But in IRB it's not.

Answer 1

You can use group_by , and transform_values to transform the values inside each hash, also using sort_by plus to_h :

given.transform_values { |value| value.sort.to_h }.sort.to_h

# {"ipsum"=>{:GR=>"foo", :ZZ=>"foo"}, "lorem"=>{:AA=>"foo", :BB=>"foo", :GR=>"foo"}}

You're getting an error because when iterating over a hash, you have to local variables within the block scope to use, the key and its value, you're assigning only one (topic) and trying to get its key, which would be trying to access a key in:

["lorem", {:AA=>"foo", :GR=>"foo", :BB=>"foo"}]

Which isn't possible as is an array. You can update your code to:

given.each do |topic, value|
  ...
end

But anyway you'll need a way to store the changes or updated and sorted version of that topic values.

Answer 2

given_hash =  {"lorem"=>{:AA=>"foo", :GR=>"foo", :BB=>"foo"}, "ipsum"=>{:ZZ=>"foo", :GR=>"foo"}} 

Get keys

given_hash.keys
=> ["lorem", "ipsum"]

New sorted hash

new_hash = {}
given_hash.keys.sort.each do |sorted_key|
  new_hash[sorted_key] = given[sorted_key]
end

 => {"ipsum"=>{:ZZ=>"foo", :GR=>"foo"}, "lorem"=>{:AA=>"foo", :GR=>"foo", :BB=>"foo"}} 

There can be a better way to do this.