GV

GeezerVison

The World Wide Web, restored to 800 pixels of glory.

Home|About|Gaming cabinet|Archives|How it works|Starter sites

On this site

  • Sign in
  • ActionsCI/CD and automation
  • CodespacesCloud development environments
  • All Features
  • Documentation
  • Training
  • Certifications
  • Build with Copilot
  • Customize Copilot
  • Integrations
  • Trending repos
  • GitHub Sponsors
  • Developer articles
  • Enterprises

This view

  • Original page
  • New address

GeezerVison is showing github.com — gh-161803: Document that pickle's file.write() receives bytes-like objects by eachimei · Pull Request #161804 · python/cpython

Conversation

@eachimei

@eachimei eachimei commented Nov 11, 2026 •
edited
Loading

Uh oh!

There was an error while loading. Please reload this page.

Copy link
Copy Markdown

The Pickler file contract says write() "accepts a single bytes argument". With protocols 4 and 5 that is inaccurate: both the C and the pure-Python picklers can pass bytearray, memoryview or PickleBuffer objects, and custom file objects that call len(data) then fail. See gh-161803; gh-88605 is the same problem in bz2/lzma.

This PR:

  • changes the wording to "bytes-like object" in Doc/library/pickle.rst, Lib/pickle.py and the two Modules/_pickle.c docstrings, and regenerates the clinic output;
  • adds a short note recommending memoryview(data).nbytes for byte counts.

Docs only; no behaviour change.

  • Issue: pickle docs: Pickler's file.write() can receive bytes-like objects, not only bytes #161803

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
All reactions
@eachimei
pythongh-161803: Document that pickle's file.write() receives bytes-l…
7afae72 
…ike objects

The Pickler file contract said write() accepts a single bytes argument,
but with protocols 4 and 5 both picklers may pass bytearray, memoryview
or PickleBuffer objects.

Co-authored-by: Copilot <[email protected]>
@python-cla-bot

python-cla-bot Bot commented Nov 11, 2026 •
edited
Loading

Uh oh!

There was an error while loading. Please reload this page.

Copy link
Copy Markdown

All commit authors signed the Contributor License Agreement.

CLA signed
All reactions

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
@bedevere-app bedevere-app Bot mentioned this pull request Nov 11, 2026
pickle docs: Pickler's file.write() can receive bytes-like objects, not only bytes #161803
Open
@bedevere-app

bedevere-app Bot commented Nov 11, 2026

Copy link
Copy Markdown

Most changes to Python require a NEWS entry. Add one using the blurb_it web app or the blurb command-line tool.

If this change has little impact on Python users, wait for a maintainer to apply the skip news label instead.
All reactions

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
@bedevere-app bedevere-app Bot added the awaiting review label Nov 11, 2026
@eachimei
Add NEWS entry
bc120d7
@eachimei
eachimei force-pushed the gh-161803-pickle-write-bytes-like branch from 8dc3d5e to bc120d7 Compare November 11, 2026 10:26
@read-the-docs-community

read-the-docs-community Bot commented Nov 11, 2026

Copy link
Copy Markdown

Documentation build overview

📚 cpython-previews | 🛠️ Build #35809842 | 📁 Comparing bc120d7 against main (de9a4fb)

  🔍 Preview build  

2 files changed
± library/pickle.html
± whatsnew/changelog.html
All reactions

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Reviewers

No reviews

Uh oh!

There was an error while loading. Please reload this page.

Assignees

No one assigned

Labels

awaiting review

Projects

None yet

Milestone

No milestone

Development

Successfully merging this pull request may close these issues.

Uh oh!

There was an error while loading. Please reload this page.

1 participant

@eachimei
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
You are visitor 01402503 — GeezerVison does not store the pages you look up.
Best viewed with Netscape Navigator 4.7 or Internet Explorer 6 at 800×600. No cookies required.