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

:class:`bytes`, and decoding:term:`bytes-like objects <bytes-like object>` or

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

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)

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)

..versionadded::3.13

The legacy interface:

.. _base64-legacy:

Legacy Interface

..function::decode(input, output)