Issue #22341: Drop Python 2 workaround and document CRC initial value

Also align the parameter naming in binascii to be consistent with zlib.

1 files changed, 11 insertions, 12 deletions

diff --git a/Doc/library/binascii.rst b/Doc/library/binascii.rst
index e3f134b..b3b4aac 100644
--- a/Doc/library/binascii.rst
+++ b/Doc/library/binascii.rst
@@ -110,15 +110,16 @@ The :mod:`binascii` module defines the following functions:
    possibly the last fragment).
 
 
-.. function:: crc_hqx(data, crc)
+.. function:: crc_hqx(data, value)
 
-   Compute the binhex4 crc value of *data*, starting with an initial *crc* and
-   returning the result.
+   Compute the binhex4 crc value of *data*, starting with *value* as the
+   initial crc, and return the result.
 
 
-.. function:: crc32(data[, crc])
+.. function:: crc32(data[, value])
 
-   Compute CRC-32, the 32-bit checksum of data, starting with an initial crc.  This
+   Compute CRC-32, the 32-bit checksum of *data*, starting with an
+   initial CRC of *value*.  The default initial CRC is zero.  The algorithm
    is consistent with the ZIP file checksum.  Since the algorithm is designed for
    use as a checksum algorithm, it is not suitable for use as a general hash
    algorithm.  Use as follows::
@@ -126,15 +127,13 @@ The :mod:`binascii` module defines the following functions:
       print(binascii.crc32(b"hello world"))
       # Or, in two pieces:
       crc = binascii.crc32(b"hello")
-      crc = binascii.crc32(b" world", crc) & 0xffffffff
+      crc = binascii.crc32(b" world", crc)
       print('crc32 = {:#010x}'.format(crc))
 
-.. note::
-   To generate the same numeric value across all Python versions and
-   platforms use crc32(data) & 0xffffffff.  If you are only using
-   the checksum in packed binary format this is not necessary as the
-   return value is the correct 32bit binary representation
-   regardless of sign.
+   .. versionchanged:: 3.0
+      The result is always unsigned.
+      To generate the same numeric value across all Python versions and
+      platforms, use ``crc32(data) & 0xffffffff``.
 
 
 .. function:: b2a_hex(data)