typing: Confusing that BinaryIO and IO[bytes] cannot be used interchangeably

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#86,678 2 comments 0 reactions 0 assignees View on GitHub

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
25/100
Issue type
Bug
Clarity
Needs clarification
Activity status
Stale
Tech stack
python
Domain
developer-experience

Research direction

The issue identifies Python's Lib component and targets Python 3.10, but names no file, test, or reproduction. Begin by reproducing the reported incompatibility between BinaryIO and IO[bytes], then determine the intended typing behavior before locating the relevant implementation and tests. Done means the interchangeability question has a documented, tested resolution.

Written by the indexing model from the issue text.

Description

3.10 stdlib topic-typing type-bug
BPO 42512
Nosy @conchylicultor

Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.

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GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2020-11-30.11:17:54.194>
labels = ['type-bug', 'library', '3.10']
title = 'typing: Confusing that BinaryIO and IO[bytes] cannot be used interchangeably'
updated_at = <Date 2020-11-30.11:34:54.839>
user = 'https://github.com/conchylicultor'

bugs.python.org fields:

activity = <Date 2020-11-30.11:34:54.839>
actor = 'vstinner'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2020-11-30.11:17:54.194>
creator = 'conchylicultor'
dependencies = []
files = []
hgrepos = []
issue_num = 42512
keywords = []
message_count = 1.0
messages = ['382143']
nosy_count = 1.0
nosy_names = ['conchylicultor']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue42512'
versions = ['Python 3.10']

Dominant language
Python
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Merged PRs (30d)
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