[Python-Dev] Add transform() and untranform() methods (original) (raw)

Terry Reedy tjreedy at udel.edu
Fri Nov 15 02:35:29 CET 2013

On 11/14/2013 6:03 PM, Nick Coghlan wrote:

You have to get it out of your head that codecs are just about text and and binary data.

99+% of the current codec module doc leads one to that impression. The fact that codecs are expected to have a file reader and writer and that the default 'strict' error handler is specified in 2 out of the 3 mostly redundant lists as raising a UnicodeError reinforces the impression.

They're not: they're arbitrary type transforms, and MAL deliberately wrote the module that way.

Generic functions are quite pythonic. However, I am not sure how much benefit there is to registering an arbitrary pair of bijective functions

This is completely the wrong approach. There's zero justification for adding new builtin methods for this use case - encoding and decoding are generic operations, they should use functions not methods.

Making 2&3 code easier is certainly a good reason for the codecs approach.

The next planned commit (to restore the binary codec aliases) is a behavioural change - that's why I posted to the list about it (it received only two responses, both +1)

If I understand correctly, I am mildly +1, but did not respond, thinking that 2 to 0 was sufficient response for you to continue ;-).

-- Terry Jan Reedy

More information about the Python-Dev mailing list