homepage

One last thing, a quick & dirty solution that works today, if you don't mind accessing private internals of stdlib classes, and don't mind giving up the performance of _io for _pyio, and don't need a solution for binary files:
class MyTextIOWrapper(_pyio.TextIOWrapper):
 def readrecord(self, sep):
 readnl, self._readnl = self._readnl, sep
 try:
 return self.readline()
 finally:
 self._readnl = readnl
Or, if you prefer:
class MyTextIOWrapper(_pyio.TextIOWrapper):
 def __init__(self, *args, separator, **kwargs):
 super().__init__(*args, **kwargs)
 self._readnl = separator
For binary files, there's no solution quite as simple; you need to write your own readline method by copying and pasting the one from _pyio.RawIOBase, and the modifications to use an arbitrary separator aren't quite as trivial as they look at first (at least if you want multi-byte separators).