Good cross-version ASCII serialisation protocol for simple types

[Paul Moore]

I need to transfer some data (nothing fancy, some dictionaries, strings, numbers and lists, basically) between 2 Python processes. However, the data (string values) is potentially not ASCII, but the transport is (I'm piping between 2 processes, but thanks to nasty encoding issues, the only characters I can be sure won't be mangled are ASCII).

What's the best ASCII-only protocol to use that's portable between versions of Python back to about 2.6/2.7 and in the stdlib, so I don't need external modules?

At the moment, I'm using

encoded = json.dumps([ord(c) for c in json.dumps(obj)])
decoded = json.loads(''.join([chr(n) for n in json.loads(encoded)]))

The double-encoding ensures that non-ASCII characters don't make it into the result.

This works fine, but is there something simpler (i.e., less of a hack!) that I could use? (Base64 and the like don't work because they encode bytes->strings, not strings->strings).

Thanks,
Paul