Also hardened the text format printer against invalid UTF-8 in string fields. The output string will always be valid UTF-8, even if string fields contain invalid UTF-8.
PiperOrigin-RevId: 600990001
- Remove PY25 cruft.
- Selectively apply cleanups from 'python-modernize':
- New exception syntax.
- Use 'six' to handle module renames.
- Use 'six' to handle text / binary stuff.
This PR covers most of the work from #66 which falls inside `python`
(rather than the Python code generation stuff in 'src').