code: def path_exists(source, path, separator='/'):
      
      if path == separator and isinstance(source, dict):
          return True
      parts = path.strip(separator).split(separator)
      if not parts:
          return False
      current = source
      for part in parts:
          if not isinstance(current, dict):
              return False
          if part not in current:
              return False
          current = current[part]
      return True
docs: Check a dict for the existence of a value given a path to it.
  
      :param source: a dict to read data from
      :param path: a key or path to a key (path is delimited by `separator`)
      :keyword separator: the separator used in the path (ex. Could be "." for a
          json/mongodb type of value)