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Diffstat (limited to 'Doc/library/codecs.rst')
| -rw-r--r-- | Doc/library/codecs.rst | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/Doc/library/codecs.rst b/Doc/library/codecs.rst index 6e249ec..74b24e1 100644 --- a/Doc/library/codecs.rst +++ b/Doc/library/codecs.rst @@ -977,10 +977,14 @@ e.g. ``'utf-8'`` is a valid alias for the ``'utf_8'`` codec. Some common encodings can bypass the codecs lookup machinery to improve performance. These optimization opportunities are only - recognized by CPython for a limited set of aliases: utf-8, utf8, - latin-1, latin1, iso-8859-1, mbcs (Windows only), ascii, utf-16, - and utf-32. Using alternative spellings for these encodings may - result in slower execution. + recognized by CPython for a limited set of (case insensitive) + aliases: utf-8, utf8, latin-1, latin1, iso-8859-1, iso8859-1, mbcs + (Windows only), ascii, us-ascii, utf-16, utf16, utf-32, utf32, and + the same using underscores instead of dashes. Using alternative + aliases for these encodings may result in slower execution. + + .. versionchanged:: 3.6 + Optimization opportunity recognized for us-ascii. Many of the character sets support the same languages. They vary in individual characters (e.g. whether the EURO SIGN is supported or not), and in the |