ruby on rails transform_keys or deep_symbolize_keys

# 将hash的键转化为symbol格式
hash = { 'person' => { 'name' => 'Rob', 'age' => '28' } }
hash.deep_symbolize_keys
# => {:person=>{:name=>"Rob", :age=>"28"}}

# 将hash的键转化为string格式
h = { a: 1, b: 2, c: 3 }
h.transform_keys {|k| k.to_s }  
#=> { "a" => 1, "b" => 2, "c" => 3 }
h.transform_keys(&:to_s)        
#=> { "a" => 1, "b" => 2, "c" => 3 }
h.transform_keys.with_index {|k, i| "#{k}.#{i}" }
#=> { "a.0" => 1, "b.1" => 2, "c.2" => 3 }