code: def dict_deep_merge(a, b, path=None):
      
      if path is None:
          path = []
      for key in b:
          if key in a:
              if isinstance(a[key], dict) and isinstance(b[key], dict):
                  dict_deep_merge(a[key], b[key], path + [str(key)])
              elif a[key] == b[key]:
                  # Key conflict, but equal value.
                  pass
              else:
                  # Key/value conflict. Prioritize b over a.
                  a[key] = b[key]
          else:
              a[key] = b[key]
      return a
docs: Deep-merge dictionary `b` into dictionary `a`.
  
      Kudos to http://stackoverflow.com/a/7205107/145400