An open source multi-tool for exploring and publishing data https://datasette.io
  • Python 79.4%
  • JavaScript 11.4%
  • HTML 6.2%
  • CSS 2.7%
  • Shell 0.1%
Find a file
Alex Garcia e24a2c122f Link block=False write spans to their enqueuer instead of parenting them
A block=False write returns without awaiting the reply future, so the
enclosing db.query span finishes - and exports - before db.write.queue_wait
and db.write.execute even exist. They were still parented to it, which
produced a child bar ending ~50ms after its already-closed parent: legal
OpenTelemetry, but it renders as nonsense in a trace UI.

Parenting asserts containment; a link asserts causation without containment.
The enqueueing request causes the write without containing it, which is
exactly what a span link is for. So for block=False both write spans are now
roots - started with an explicit empty Context, so the write thread's ambient
context cannot supply a parent either - each carrying one link back to the
enqueueing span. block=True is untouched, since there the caller really does
await the reply and containment is accurate.

The link carries no attributes. There is only one kind of link here, so
naming the relationship would be a constant conveying nothing the link's
existence does not already say.

Accepted trade-off: a linked span will not appear inside the request's
waterfall in most trace UIs. It shows up as its own trace with a "linked
from" reference rather than a bar under the request. For a fire-and-forget
write whose latency the request never pays, that is the right trade -
correctness over at-a-glance nesting for a case the request-latency view was
never accurate for anyway.

This does add root traces, which looks like it cuts against the startup span
work that spent its whole diff removing them. The difference is reachability:
those roots were orphans, whereas these are reachable from the request that
caused them via the link.

Nothing in core issues block=False writes today - it is a plugin-facing path
- so this changes no trace Datasette produces on its own.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-01 16:24:35 -07:00
.github check-latest: true, add 3.15 to test matrix, to test RCs (#2895) 2026-09-01 13:37:15 -07:00
datasette Link block=False write spans to their enqueuer instead of parenting them 2026-09-01 16:24:35 -07:00
demos Fixed an unnecessary f-string 2024-02-04 10:15:21 -08:00
docs Release 1.0a38 2026-08-06 11:20:25 -07:00
tests Link block=False write spans to their enqueuer instead of parenting them 2026-09-01 16:24:35 -07:00
.coveragerc Configure code coverage, refs #841, #843 2020-06-13 13:48:23 -07:00
.dockerignore Build Dockerfile with SpatiaLite 5, refs #1249 2021-03-26 21:27:40 -07:00
.git-blame-ignore-revs Ignore Black commits in git blame, refs #1716 2022-04-22 14:58:46 -07:00
.gitattributes New explicit versioning mechanism 2020-10-28 20:38:15 -07:00
.gitignore Ignore ignored/ directory 2026-06-25 21:20:29 -07:00
.isort.cfg Used isort to re-order my imports 2018-05-14 00:04:23 -03:00
.prettierrc .prettierrc, refs #1166 2020-12-31 13:25:44 -08:00
.readthedocs.yaml dependency-groups and uv (#2611) 2025-12-11 17:32:58 -08:00
CODE_OF_CONDUCT.md Add code of conduct again 2022-03-15 08:38:42 -07:00
codecov.yml codecov should not be blocking 2020-07-02 21:29:32 -07:00
Dockerfile Upgrade Docker images to Python 3.11, closes #1853 2022-10-25 12:04:53 -07:00
Justfile Add Prettier check to lint recipe (#2821) 2026-07-03 09:50:35 -07:00
LICENSE Initial commit 2017-10-22 17:39:03 -07:00
MANIFEST.in Include LICENSE in sdist (#1043) 2020-10-23 13:54:34 -07:00
package-lock.json Bump rollup from 3.29.5 to 3.30.0 (#2651) 2026-03-30 10:54:48 -07:00
package.json Bump rollup from 3.29.5 to 3.30.0 (#2651) 2026-03-30 10:54:48 -07:00
pyproject.toml Add opentelemetry-api dependency and datasette/telemetry.py scaffolding 2026-09-01 16:24:15 -07:00
pytest.ini Initial Playwright setup plus first test 2026-06-14 16:39:55 -07:00
README.md Replace Glitch with Codespaces, closes #2488 2025-05-28 19:17:22 -07:00
ruff.toml Upgrade to ruff>=0.16.0 (#2857) 2026-07-25 15:47:08 -07:00
setup.cfg Switch to ruff and fix all lint errors, refs #2630 2026-01-23 20:43:16 -08:00
test-in-pyodide-with-shot-scraper.sh Test against pyodide/v314.0.0 2026-06-22 10:11:56 -07:00

Datasette

PyPI Changelog Python 3.x Tests Documentation Status License docker: datasette discord

An open source multi-tool for exploring and publishing data

Datasette is a tool for exploring and publishing data. It helps people take data of any shape or size and publish that as an interactive, explorable website and accompanying API.

Datasette is aimed at data journalists, museum curators, archivists, local governments, scientists, researchers and anyone else who has data that they wish to share with the world.

Explore a demo, watch a video about the project or try it out on GitHub Codespaces.

Want to stay up-to-date with the project? Subscribe to the Datasette newsletter for tips, tricks and news on what's new in the Datasette ecosystem.

Installation

If you are on a Mac, Homebrew is the easiest way to install Datasette:

brew install datasette

You can also install it using pip or pipx:

pip install datasette

Datasette requires Python 3.8 or higher. We also have detailed installation instructions covering other options such as Docker.

Basic usage

datasette serve path/to/database.db

This will start a web server on port 8001 - visit http://localhost:8001/ to access the web interface.

serve is the default subcommand, you can omit it if you like.

Use Chrome on OS X? You can run datasette against your browser history like so:

 datasette ~/Library/Application\ Support/Google/Chrome/Default/History --nolock

Now visiting http://localhost:8001/History/downloads will show you a web interface to browse your downloads data:

Downloads table rendered by datasette

metadata.json

If you want to include licensing and source information in the generated datasette website you can do so using a JSON file that looks something like this:

{
    "title": "Five Thirty Eight",
    "license": "CC Attribution 4.0 License",
    "license_url": "http://creativecommons.org/licenses/by/4.0/",
    "source": "fivethirtyeight/data on GitHub",
    "source_url": "https://github.com/fivethirtyeight/data"
}

Save this in metadata.json and run Datasette like so:

datasette serve fivethirtyeight.db -m metadata.json

The license and source information will be displayed on the index page and in the footer. They will also be included in the JSON produced by the API.

datasette publish

If you have Heroku or Google Cloud Run configured, Datasette can deploy one or more SQLite databases to the internet with a single command:

datasette publish heroku database.db

Or:

datasette publish cloudrun database.db

This will create a docker image containing both the datasette application and the specified SQLite database files. It will then deploy that image to Heroku or Cloud Run and give you a URL to access the resulting website and API.

See Publishing data in the documentation for more details.

Datasette Lite

Datasette Lite is Datasette packaged using WebAssembly so that it runs entirely in your browser, no Python web application server required. Read more about that in the Datasette Lite documentation.