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(python2.1-lib.info)Codec Objects

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Codec Objects
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The `Codec' class defines these methods which also define the function
interfaces of the stateless encoder and decoder:

`encode(input[, errors])'
     Encodes the object INPUT and returns a tuple (output object,
     length consumed).

     ERRORS defines the error handling to apply. It defaults to
     `'strict'' handling.

     The method may not store state in the `Codec' instance. Use
     `StreamCodec' for codecs which have to keep state in order to make
     encoding/decoding efficient.

     The encoder must be able to handle zero length input and return an
     empty object of the output object type in this situation.

`decode(input[, errors])'
     Decodes the object INPUT and returns a tuple (output object,
     length consumed).

     INPUT must be an object which provides the `bf_getreadbuf' buffer
     slot.  Python strings, buffer objects and memory mapped files are
     examples of objects providing this slot.

     ERRORS defines the error handling to apply. It defaults to
     `'strict'' handling.

     The method may not store state in the `Codec' instance. Use
     `StreamCodec' for codecs which have to keep state in order to make
     encoding/decoding efficient.

     The decoder must be able to handle zero length input and return an
     empty object of the output object type in this situation.

The `StreamWriter' and `StreamReader' classes provide generic working
interfaces which can be used to implement new encodings submodules very
easily. See `encodings.utf_8' for an example on how this is done.