Address reviewer feedback

- Update docs to refer to "Base 32" and "Base32"
- Update docs to better explain `binascii.a2b_base32()`
- Inline helper function in `base64`
- Add forgotten tests for presence of alphabet module globals

Author: kangtastic

Doc/library/binascii.rst

@@ -182,16 +182,21 @@ The :mod:`!binascii` module defines the following functions:
 
    .. versionadded:: 3.15
 
+
 .. function:: a2b_base32(string, /, *, alphabet=BASE32_ALPHABET)
 
    Convert base32 data back to binary and return the binary data.
 
-   Valid base32 data:
+   Valid base32 data contains characters from the base32 alphabet specified
+   in :rfc:`4648` in groups of eight (if necessary, the final group is padded
+   to eight characters with ``=``). Each group encodes 40 bits of binary data
+   in the range from ``0`` to ``2 ** 40 - 1``, inclusive.
 
-   * Conforms to :rfc:`4648`.
-   * Contains only characters from the base32 alphabet.
-   * Contains no excess data after padding (including excess padding, newlines, etc.).
-   * Does not start with padding.
+   .. note::
+      By default, this function does not map lowercase characters (which are
+      invalid in standard base32) to their uppercase counterparts, nor does
+      it contextually map ``0`` to ``O`` and ``1`` to ``I``/``L`` as
+      :rfc:`4648` allows.
 
    Optional *alphabet* must be a :class:`bytes` object of length 32 which
    specifies an alternative alphabet.
@@ -202,7 +207,7 @@ The :mod:`!binascii` module defines the following functions:
 
 .. function:: b2a_base32(data, /, *, alphabet=BASE32_ALPHABET)
 
-   Convert binary data to a line(s) of ASCII characters in base32 coding,
+   Convert binary data to a line of ASCII characters in base32 coding,
    as specified in :rfc:`4648`. The return value is the converted line.
 
    Optional *alphabet* must be a :term:`bytes-like object` of length 32 which
@@ -356,13 +361,13 @@ The :mod:`!binascii` module defines the following functions:
 
 .. data:: BASE32_ALPHABET
 
-   The base32 alphabet according to :rfc:`4648`.
+   The Base 32 alphabet according to :rfc:`4648`.
 
    .. versionadded:: next
 
 .. data:: BASE32HEX_ALPHABET
 
-   The "Extended Hex" base32hex alphabet according to :rfc:`4648`.
+   The "Extended Hex" Base 32 alphabet according to :rfc:`4648`.
 
    .. versionadded:: next
 

Lib/base64.py

@@ -207,10 +207,12 @@ def urlsafe_b64decode(s):
 0 and 1 are not allowed in the input.
 '''
 
-def _b32decode_prepare(s, casefold=False, map01=None):
+def b32encode(s):
+    return binascii.b2a_base32(s)
+b32encode.__doc__ = _B32_ENCODE_DOCSTRING.format(encoding='base32')
+
+def b32decode(s, casefold=False, map01=None):
     s = _bytes_from_decode_data(s)
-    if len(s) % 8:
-        raise binascii.Error('Incorrect padding')
     # Handle section 2.4 zero and one mapping.  The flag map01 will be either
     # False, or the character to map the digit 1 (one) to.  It should be
     # either L (el) or I (eye).
@@ -220,15 +222,6 @@ def _b32decode_prepare(s, casefold=False, map01=None):
         s = s.translate(bytes.maketrans(b'01', b'O' + map01))
     if casefold:
         s = s.upper()
-    return s
-
-
-def b32encode(s):
-    return binascii.b2a_base32(s)
-b32encode.__doc__ = _B32_ENCODE_DOCSTRING.format(encoding='base32')
-
-def b32decode(s, casefold=False, map01=None):
-    s = _b32decode_prepare(s, casefold, map01)
     return binascii.a2b_base32(s)
 b32decode.__doc__ = _B32_DECODE_DOCSTRING.format(encoding='base32',
                                         extra_args=_B32_DECODE_MAP01_DOCSTRING)
@@ -238,8 +231,10 @@ def b32hexencode(s):
 b32hexencode.__doc__ = _B32_ENCODE_DOCSTRING.format(encoding='base32hex')
 
 def b32hexdecode(s, casefold=False):
+    s = _bytes_from_decode_data(s)
     # base32hex does not have the 01 mapping
-    s = _b32decode_prepare(s, casefold)
+    if casefold:
+        s = s.upper()
     return binascii.a2b_base32(s, alphabet=binascii.BASE32HEX_ALPHABET)
 b32hexdecode.__doc__ = _B32_DECODE_DOCSTRING.format(encoding='base32hex',
                                                     extra_args='')

Lib/test/test_binascii.py

@@ -74,6 +74,10 @@ def test_constants(self):
                          b'abcdefghijklmnopqrstuvwxyz'
                          b'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
                          b'.-:+=^!/*?&<>()[]{}@%$#')
+        self.assertEqual(binascii.BASE32_ALPHABET,
+                         b'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567')
+        self.assertEqual(binascii.BASE32HEX_ALPHABET,
+                         b'0123456789ABCDEFGHIJKLMNOPQRSTUV')
 
     def test_functions(self):
         # Check presence of all functions

Modules/binascii.c

@@ -1672,7 +1672,7 @@ binascii.b2a_base32
     *
     alphabet: Py_buffer(c_default="{NULL, NULL}") = BASE32_ALPHABET
 
-base32-code line of data.
+Base32-code line of data.
 [clinic start generated code]*/
 
 static PyObject *