On 8/27/2014 6:08 PM, Stephen J. Turnbull wrote:

Glenn Linderman writes:
 > On 8/26/2014 4:31 AM, MRAB wrote:
 > > On 2014-08-26 03:11, Stephen J. Turnbull wrote:
 > >> Nick Coghlan writes:

 > > How about:
 > >
 > >     replace_surrogate_escapes(s, replacement='\uFFFD')
 > >
 > > If you want them removed, just pass an empty string as the
 > > replacement.

That seems better to me (I had too much C for breakfast, I think).

 > And further, replacement could be a vector of 128 characters, to do
 > immediate transcoding,

Using what encoding?

The vector would contain the transcoding. Each lone surrogate would map to a character in the vector.

If you knew that much, why didn't you use
(write, if necessary) an appropriate codec?  I can't envision this
being useful.

If the data format describes its encoding, possibly containing data from several encodings in various spots, then perhaps it is best read as binary, and processed as binary until those definitions are found.

But an alternative would be to read with surrogate escapes, and then when the encoding is determined, to transcode the data. Previously, a proposal was made to reverse the surrogate escapes to the original bytes, and then apply the (now known) appropriate codec. There are not appropriate codecs that can convert directly from surrogate escapes to the desired end result. This technique could be used instead, for single-byte, non-escaped encodings. On the other hand, writing specialty codecs for the purpose would be more general.