Bytes-like object or Buffer type annotaion

Question

How do I annotate a bytes-like object or a Buffer?

There is no interface for the buffer protocol but I wish to accept all buffers in a function of mine.

I don't mind if it's only mypy-specific.

score 3 · Answer 1 · 2017-09-21T13:22:52.777

3

Currently (as of Python 3.6) the "Buffer Protocol" is a C API thing only - you can't even talk about it in regular Python code.

I would use Any for now.

edited Sep 21 '17 at 13:22

answered Sep 21 '17 at 13:15

the bug can easily found by searching for "typing buffer" on bugs.python.org – Sep 21 '17 at 13:28
I would use Union of the expected types, e.g. Union[bytes, bytearray] – proski May 21 '23 at 17:22
@proski incorrect as plenty of others implement it. It is a semi-good workaround though. – Bharel Jun 12 '23 at 18:10

score 3 · Accepted Answer · answered Jun 12 '23 at 18:09

3

Starting with Python 3.12, collections.abc.Buffer can be used like so:

from collections.abc import Buffer

def foo(buffer: Buffer):
    pass

answered Jun 12 '23 at 18:09

Bharel

Wow, it took them 8 years to come up with a type for it (since 3.5). I like Python, but type hints are like 'the interpreter doesn't care, we don't care, neither should you'. – Abhijit Sarkar Jun 22 '23 at 18:50
@AbhijitSarkar actually nowadays type-hints are used just about everywhere. CPython core devs tend to develop them more and more. – Bharel Jun 23 '23 at 00:26

2 Answers2