Re: Resolving the python 2 -> python 3 mess

>
> A possible gotcha in this approach is if there are any python 2/3
> incompatibilities that would not manifest as syntax errors or
> obvious runtime errors, but would allow old code to execute and
> silently do the wrong thing. One would hope that the Python crowd
> weren't dumb enough to do that, but I don't know whether it's true.
> If there are nasty cases like that, maybe what we have to do is allow
> plpythonu/plpython2u functions to be dumped and reloaded into a
> python-3-only install, but refuse to execute them until they've
> been converted.
>

Unfortunately, I think there are cases like that. The shift to Unicode as
the default string means that some functions that used to return a `str`
now return a `bytes` (I know of this in the hashlib and base64 modules, but
probably also in URL request data and others), and to use a `bytes` in
string manipulation you have to first explicitly convert it to some string
encoding. So things like a function that wraps around a python crypto
library would be the exact places where those was-str-now-bytes functions
would be used.