NamedTemporaryFile is not its own iterator.

[xzy3]

BPO	41270
Nosy	@brettcannon, @pitrou, @peterjc, @serhiy-storchaka, @tontinton, @xzy3
PRs	bpo-41270 Added __next__ to _TemporaryFileWrapper #21434 bpo-41273: asyncio's proactor read transport's better performance by using recv_into instead of recv #21439 bpo-41273: asyncio's proactor read transport's better performance by using recv_into instead of recv #21442 bpo-41270: Making NamedTemporaryFile act as its own iterator to mimic… #22766

^{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 2020-07-10.13:58:42.924>
labels = ['type-feature', 'library', '3.11']
title = 'NamedTemporaryFile is not its own iterator.'
updated_at = <Date 2021-11-30.13:15:38.991>
user = 'https://github.com/xzy3'

bugs.python.org fields:

activity = <Date 2021-11-30.13:15:38.991>
actor = 'serhiy.storchaka'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2020-07-10.13:58:42.924>
creator = 'xzy3'
dependencies = []
files = []
hgrepos = []
issue_num = 41270
keywords = ['patch']
message_count = 2.0
messages = ['373467', '407372']
nosy_count = 7.0
nosy_names = ['brett.cannon', 'pitrou', 'maubp', 'python-dev', 'serhiy.storchaka', 'tontinton', 'xzy3']
pr_nums = ['21434', '21439', '21442', '22766']
priority = 'normal'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue41270'
versions = ['Python 3.11']

[xzy3]

_TemporaryFileWrapper does not proxy next to the underlying file object. There was a discussion on the mailing list in 2016 mentioning this, however it seems it was dropped without a consensus. Biopython encountered this issue (referenced below) and we agree it violates our assumptions about how the NamedTemporaryFile should work. I think it would be fairly trivial to fix by just returning self.file.readline()

mailing list thread: https://mail.python.org/pipermail/python-list/2016-July/862590.html

biopython discussion: biopython/biopython#3031