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| -rw-r--r-- | Doc/whatsnew/whatsnew23.tex | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/Doc/whatsnew/whatsnew23.tex b/Doc/whatsnew/whatsnew23.tex index 975079b..aced4e1 100644 --- a/Doc/whatsnew/whatsnew23.tex +++ b/Doc/whatsnew/whatsnew23.tex @@ -492,7 +492,27 @@ strings \samp{True} and \samp{False} instead of \samp{1} and \samp{0}. %====================================================================== \section{PEP 293: Codec Error Handling Callbacks} -XXX write this section +When encoding a Unicode string into a byte string, unencodable +characters may be encountered. So far, Python allowed to specify the +error processing as either ``strict'' (raise \code{UnicodeError}, +default), ``ignore'' (skip the character), or ``replace'' (with +question mark). It may be desirable to specify an alternative +processing of the error, e.g. by inserting an XML character reference +or HTML entity reference into the converted string. + +Python now has a flexible framework to add additional processing +strategies; new error handlers can be added with +\function{codecs.register_error}. Codecs then can access the error +handler with \code{codecs.lookup_error}. An equivalent C API has been +added for codecs written in C. The error handler gets various state +information, such as the string being converted, the position in the +string where the error was detected, and the target encoding. It can +then either raise an exception, or return a replacement string. + +Two additional error handlers have been implemented using this +framework: ``backslashreplace'' using Python backslash quoting to +represent the unencodable character, and ``xmlcharrefreplace'' emits +XML character references. \begin{seealso} |