gistfile1.txt

a = {zzz: [{b: 1, c: 2}, {b:3, c:4}]}
 
  # slight variant on https://stackoverflow.com/questions/10676608/ruby-deleting-all-instances-of-a-particular-key-from-hash-of-hashes
  class Hash
   def deep_reject_key!(key)
     keys.each {|k| delete(k) if k == key || self[k] == self[key] }

     values.each do |v| 
       v.deep_reject_key!(key) if v.is_a? Hash
       v.each {|i| i.deep_reject_key!(key) if i.is_a? Hash } if v.is_a? Array
     end
     self
   end
 end
 
 a.deep_reject_key!(:b)