From: R David Murray <rdmurray@bitdance.com>
Date: Sun, 13 Dec 2015 23:04:14 +0000 (-0500)
Subject: #25495: Clarify b2a_base64 documentation vis 57 bytes.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=b75adccd0af3a45ac63bc003af4fe6945d6cd6e4;p=python

#25495: Clarify b2a_base64 documentation vis 57 bytes.
---

diff --git a/Doc/library/binascii.rst b/Doc/library/binascii.rst
index 0f8a3dec6b..5eb7c4b8de 100644
--- a/Doc/library/binascii.rst
+++ b/Doc/library/binascii.rst
@@ -45,8 +45,10 @@ The :mod:`binascii` module defines the following functions:
 .. function:: b2a_base64(data)
 
    Convert binary data to a line of ASCII characters in base64 coding. The return
-   value is the converted line, including a newline char. The length of *data*
-   should be at most 57 to adhere to the base64 standard.
+   value is the converted line, including a newline char.  The newline is
+   added because the original use case for this function was to feed it a
+   series of 57 byte input lines to get output lines that conform to the
+   MIME-base64 standard.  Otherwise the output conforms to :rfc:`3548`.
 
 
 .. function:: a2b_qp(string[, header])
@@ -165,7 +167,7 @@ The :mod:`binascii` module defines the following functions:
 .. seealso::
 
    Module :mod:`base64`
-      Support for base64 encoding used in MIME email messages.
+      Support for RFC compliant base64-style encoding in base 16, 32, and 64.
 
    Module :mod:`binhex`
       Support for the binhex format used on the Macintosh.