How to sort a hash by nested hash values in Ruby

nested_hash_sort.rb

# Courtesy of http://www.rubyinside.com/how-to/ruby-sort-hash 
# I added the reverse (descending) sort part at the bottom.

# Sample Data
people = {
  :fred => { :name => "Fred", :age => 23 },
  :joan => { :name => "Joan", :age => 18 },
  :pete => { :name => "Pete", :age => 54 }
}

# Sort ascending
p people.sort_by { |k, v| v[:age] }
  # => [[:joan, {:name=>"Joan", :age=>18}],
  #     [:fred, {:name=>"Fred", :age=>23}],
  #     [:pete, {:name=>"Pete", :age=>54}]]

# Sort descending
p people.sort_by { |k, v| v[:age] }.reverse!