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Title: mimetypes.add_type should complain when you give it an undotted ext
Type: Stage: commit review
Components: Documentation, Library (Lib) Versions: Python 3.7
Status: open Resolution:
Dependencies: Superseder:
Assigned To: docs@python Nosy List: Jim.Jewett, docs@python, mdk, odd_bloke, rcj
Priority: normal Keywords:

Created on 2017-07-25 19:25 by odd_bloke, last changed 2022-04-11 14:58 by admin.

Pull Requests
URL Status Linked Edit
PR 2871 open odd_bloke, 2017-07-25 19:41
PR 2895 open odd_bloke, 2017-07-26 15:06
Messages (4)
msg299135 - (view) Author: Daniel Watkins (odd_bloke) * Date: 2017-07-25 19:25
import mimetypes

mimetypes.add_type('text/plain', 'manifest')

results in:

('application/x-ms-manifest', None)
('application/x-ms-manifest', None)

I (mistakenly) expected the latter print to give me "('text/plain', None)".  It doesn't because I should have prepended a . to the second add_type argument.

I think add_type should error out when given an extension without a dot-prefix, because it's extremely unlikely that code that does so is behaving as intended with the current implementation.

(At the very least, documentation should be updated to make this expectation clearer.)
msg306501 - (view) Author: Jim Jewett (Jim.Jewett) * (Python triager) Date: 2017-11-19 14:35
Ideally, use .startswith('.') Instead if find, but this is a clear UI fix. First pull request fixes doc, second fixes code. OK to apply both.
msg352266 - (view) Author: Julien Palard (mdk) * (Python committer) Date: 2019-09-13 09:45
I think we should deprecate calling `add_type` with an empty `ext`, as I don't think it's a feature, more a side effect of the current implementation.

But as some may use it like a feature, I asked the current PR to emit a warning, to not break the current implementations.

To be able to simplify in the future, why not deprecating empty `ext` so we can remove it in a few versions?
msg352286 - (view) Author: Julien Palard (mdk) * (Python committer) Date: 2019-09-13 10:59
I just found a case where the empty mime type is actually usefull, it's in Lib/http/

    extensions_map = mimetypes.types_map.copy()
        '': 'application/octet-stream', # Default
        '.py': 'text/plain',
        '.c': 'text/plain',
        '.h': 'text/plain',

It does *not* uses add_type, but demos the fact that the empty type may be usefull from time to time, maybe don't warn and don't deprecate it at all.
Date User Action Args
2022-04-11 14:58:49adminsetgithub: 75223
2019-09-13 10:59:42mdksetmessages: + msg352286
2019-09-13 09:45:12mdksetnosy: + mdk
messages: + msg352266
2017-11-19 14:35:40Jim.Jewettsetnosy: + Jim.Jewett

messages: + msg306501
stage: commit review
2017-07-26 15:06:58odd_blokesetpull_requests: + pull_request2948
2017-07-26 03:55:37Mariattasetassignee: docs@python

nosy: + docs@python
components: + Documentation
versions: + Python 3.7
2017-07-25 19:41:43odd_blokesetpull_requests: + pull_request2922
2017-07-25 19:30:56rcjsetnosy: + rcj
2017-07-25 19:25:41odd_blokecreate