Wrap an open stream with io.TextIOWrapper
Use codecs.getreader to produce a wrapper object:
text_stream = codecs.getreader("utf-8")(bytes_stream)Works on Python 2 and Python 3.
It turns out you just need to wrap your io.BytesIO in io.BufferedReader which exists on both Python 2 and Python 3.
import ioreader = io.BufferedReader(io.BytesIO("Lorem ipsum".encode("utf-8")))wrapper = io.TextIOWrapper(reader)wrapper.read() # returns Lorem ipsumThis answer originally suggested using os.pipe, but the read-side of the pipe would have to be wrapped in io.BufferedReader on Python 2 anyway to work, so this solution is simpler and avoids allocating a pipe.
Based on multiple suggestions in various forums, and experimenting with the standard library to meet the criteria, my current conclusion is this can't be done with the library and types as we currently have them.