[Python-Dev] Parametrized codecs

[Andrew Kuchling]

Are there any codecs that can take parameters at initialization time?
If not, how about supporting them?  Here's a motivating example:

import codecs
f = codecs.open('output', 'wb', encoding='DES',  # arguments to open()
                key = '...', mode = DES.ECB)
f.write('This will be encrypted\n')
f.close()

For this to work, you'd need a few changes to codecs.py.  Off the top
of my head, I think StreamReader, StreamWriter, and StreamReaderWriter
all need to grow **kwargs arguments for any additional arguments, as
do codecs.open() and codecs.lookup().

Then someone could write a DES StreamReader/Streamwriter that took a
key and feedback mode at creation time.  (codecs.Codec instances are
supposed to be stateless, right?)

--amk