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Diffstat (limited to 'Doc/library/base64.rst')
| -rw-r--r-- | Doc/library/base64.rst | 48 |
1 files changed, 37 insertions, 11 deletions
diff --git a/Doc/library/base64.rst b/Doc/library/base64.rst index 834ab2536e6..529a7242443 100644 --- a/Doc/library/base64.rst +++ b/Doc/library/base64.rst @@ -15,14 +15,9 @@ This module provides functions for encoding binary data to printable ASCII characters and decoding such encodings back to binary data. -It provides encoding and decoding functions for the encodings specified in -:rfc:`4648`, which defines the Base16, Base32, and Base64 algorithms, -and for the de-facto standard Ascii85 and Base85 encodings. - -The :rfc:`4648` encodings are suitable for encoding binary data so that it can be -safely sent by email, used as parts of URLs, or included as part of an HTTP -POST request. The encoding algorithm is not the same as the -:program:`uuencode` program. +This includes the :ref:`encodings specified in <base64-rfc-4648>` +:rfc:`4648` (Base64, Base32 and Base16) +and the non-standard :ref:`Base85 encodings <base64-base-85>`. There are two interfaces provided by this module. The modern interface supports encoding :term:`bytes-like objects <bytes-like object>` to ASCII @@ -30,7 +25,7 @@ supports encoding :term:`bytes-like objects <bytes-like object>` to ASCII strings containing ASCII to :class:`bytes`. Both base-64 alphabets defined in :rfc:`4648` (normal, and URL- and filesystem-safe) are supported. -The legacy interface does not support decoding from strings, but it does +The :ref:`legacy interface <base64-legacy>` does not support decoding from strings, but it does provide functions for encoding and decoding to and from :term:`file objects <file object>`. It only supports the Base64 standard alphabet, and it adds newlines every 76 characters as per :rfc:`2045`. Note that if you are looking @@ -46,7 +41,15 @@ package instead. Any :term:`bytes-like objects <bytes-like object>` are now accepted by all encoding and decoding functions in this module. Ascii85/Base85 support added. -The modern interface provides: + +.. _base64-rfc-4648: + +RFC 4648 Encodings +------------------ + +The :rfc:`4648` encodings are suitable for encoding binary data so that it can be +safely sent by email, used as parts of URLs, or included as part of an HTTP +POST request. .. function:: b64encode(s, altchars=None) @@ -181,6 +184,26 @@ The modern interface provides: incorrectly padded or if there are non-alphabet characters present in the input. +.. _base64-base-85: + +Base85 Encodings +----------------- + +Base85 encoding is not formally specified but rather a de facto standard, +thus different systems perform the encoding differently. + +The :func:`a85encode` and :func:`b85encode` functions in this module are two implementations of +the de facto standard. You should call the function with the Base85 +implementation used by the software you intend to work with. + +The two functions present in this module differ in how they handle the following: + +* Whether to include enclosing ``<~`` and ``~>`` markers +* Whether to include newline characters +* The set of ASCII characters used for encoding +* Handling of null bytes + +Refer to the documentation of the individual functions for more information. .. function:: a85encode(b, *, foldspaces=False, wrapcol=0, pad=False, adobe=False) @@ -262,7 +285,10 @@ The modern interface provides: .. versionadded:: 3.13 -The legacy interface: +.. _base64-legacy: + +Legacy Interface +---------------- .. function:: decode(input, output) |