Skip to content

gh-118761: Improve import time of mimetypes #126979

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
hugovk merged 4 commits into from
Nov 21, 2024
Merged

gh-118761: Improve import time of mimetypes #126979

Changes from 1 commit
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
4069061
Improve import time of mimetypes: defer urllib.parse
hugovk Nov 18, 2024
12fc4fe
Update link redirect
hugovk Nov 18, 2024
e6e4752
Improve import time of mimetypes: defer os, sys, posixpath
hugovk Nov 18, 2024
0f2ccf0
Add blurb
hugovk Nov 18, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Next Next commit
Improve import time of mimetypes: defer urllib.parse
  • Loading branch information
@hugovk
hugovk committed Nov 18, 2024
commit 4069061cb4d0e2edc501ad7c5d3223b5ca2ebc92
4 changes: 3 additions & 1 deletion Lib/mimetypes.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -26,7 +26,6 @@
import os

@danielhollas danielhollas Nov 19, 2024

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I wonder if lazy import of os module is worth it here, it is needed three times and the improvement is small and only in a special case.

@vstinner vstinner Nov 19, 2024

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Python always imports os and sys at startup. Moving import sys makes sense, it's only used by _main(). But I'm not sure about moving os.

@danielhollas danielhollas Nov 19, 2024

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

In the OP, @hugovk provides timings for when the python is run without the site.py module (python -S), in which case os and sys are not loaded I believe?

@hugovk hugovk Nov 21, 2024

Copy link
Copy Markdown
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Yes, it makes a difference with python -S, compare the last three images above.

But I'm fine reverting any of these, because I expect with site.py is by far the most usual thing.

import sys
import posixpath
import urllib.parse

try:
from _winapi import _mimetypes_read_windows_registry
Expand Down Expand Up @@ -119,6 +118,9 @@ def guess_type(self, url, strict=True):
Optional 'strict' argument when False adds a bunch of commonly found,
but non-standard types.
"""
# Lazy import to improve module import time
import urllib.parse

# TODO: Deprecate accepting file paths (in particular path-like objects).
url = os.fspath(url)
p = urllib.parse.urlparse(url)
Expand Down