Feature or enhancement

Proposal:

bytes.fromhex() should accept abytes:

>>>bytes.fromhex(b'8a3218def90a84cb4373beed87d9ba1ccc7d90d1')b'\x8a2\x18\xde\xf9\n\x84\xcbCs\xbe\xed\x87\xd9\xba\x1c\xcc}\x90\xd1'

Background:

bytes.fromhex() accepts astr:

>>>bytes.fromhex('8a3218def90a84cb4373beed87d9ba1ccc7d90d1')b'\x8a2\x18\xde\xf9\n\x84\xcbCs\xbe\xed\x87\xd9\xba\x1c\xcc}\x90\xd1'

However, it refuses to parse a byte string:

>>>bytes.fromhex(b'8a3218def90a84cb4373beed87d9ba1ccc7d90d1')Traceback (mostrecentcalllast):File"<python-input-0>",line1,in<module>bytes.fromhex(b'8a3218def90a84cb4373beed87d9ba1ccc7d90d1')~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^TypeError:fromhex()argumentmustbestr,notbytes

This requires an extra.decode(), which is rather wasteful given that thestr is not of any real use.

This came up for me in parsing the output ofgit cat-file --batch, which must be a binary stream because it contains bytes, but includes header lines like

8a3218def90a84cb4373beed87d9ba1ccc7d90d1 100644 1394

The integers are parseable directly from bytes:

>>>int(b'100644',8)33188

so it seems like an omission that the SHAs are not.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

Linked PRs

• gh-129349: Accept bytes in bytes.fromhex()/bytearray.fromhex() #129844