code: def map_keys(pvs, keys):
      
      rs = []
      for pv in pvs:
          r = dict((v, None) for k, v in keys.items())
          for k, v in pv.items():
              if k in keys:
                  r[keys[k]] = v
              r[k] = v
          rs.append(r)
      return rs
docs: Add human readable key names to dictionary while leaving any existing key names.