jsonlines
Library with helpers for the jsonlines file format
Decision gist · record as of 2026-08-14
Yes. The package is stable, production-grade, and has minimal install friction. Its single dependency and low complexity make it reliable for jsonlines I/O. The dormant maintenance status is not a blocker for basic use cases, but be aware that bug fixes or Python version compatibility updates are unlikely to be addressed quickly if issues arise.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires Python 3.8 or later.
- Low friction install with a single lightweight dependency (attrs).
- Dormant maintenance status—last release was 2023-09-01 and no commits since 2024-08-05—but the package is marked Production/Stable and has remained functional without active development.
License · maintenance · safety
BSD (permissive) — BSD permissive license allows use in most commercial and open-source projects with minimal restrictions; you must retain the license notice in distributions.
last release 2023-09-01 (1078 days) · last repo commit 2024-08-05 · 303 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 15,689,783 downloads/mo, #1,176 on PyPI
Alternatives
Verify before relying
pip install jsonlines
import jsonlines
with jsonlines.open('data.jsonl') as reader:
for obj in reader:
print(obj)- Whether the dormant status (no commits since 2024-08-05) affects reliability for new Python versions or edge cases in production use.
What it is and what it does
jsonlines is a Python library that handles the jsonlines and ndjson file formats—both of which store JSON objects as newline-delimited records, one per line. It provides a simple, Pythonic interface to read and write these formats without manually parsing line-by-line JSON. The library depends only on attrs and requires Python 3.8 or later.
The package is stable and widely used (ranked in the top 5000 PyPI packages by downloads), but maintenance is dormant—the last release was in September 2023 and there have been no commits since August 2024. For straightforward jsonlines I/O tasks, this is a reliable, low-friction choice; for projects requiring active maintenance or frequent updates, the lack of recent activity is worth noting.
Use it for
- Parse log files or event streams stored in jsonlines format for analysis or transformation.
- Write streaming JSON data to disk one record per line for efficient storage and incremental processing.
- Convert between jsonlines and Python objects in data pipelines or ETL workflows.
- Read large JSON datasets line-by-line without loading the entire file into memory.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes.
The package is stable, production-grade, and has minimal install friction. Its single dependency and low complexity make it reliable for jsonlines I/O. The dormant maintenance status is not a blocker for basic use cases, but be aware that bug fixes or Python version compatibility updates are unlikely to be addressed quickly if issues arise.
Install
jsonlines on PyPI
Before you install
Low friction install with a single lightweight dependency (attrs). Dormant maintenance status—last release was 2023-09-01 and no commits since 2024-08-05—but the package is marked Production/Stable and has remained functional without active development.
Requires Python 3.8 or later.
License in practice
BSD permissive license allows use in most commercial and open-source projects with minimal restrictions; you must retain the license notice in distributions.
Quickstart
pip install jsonlines
import jsonlines
with jsonlines.open('data.jsonl') as reader:
for obj in reader:
print(obj)Verify before relying
- Whether the dormant status (no commits since 2024-08-05) affects reliability for new Python versions or edge cases in production use.
Package facts
| License | BSD permissive |
| Python support | Supports the current Python release >=3.8 |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | 1 packageattrs |
| Maintenance | Dormant 1,078 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 15,689,783 / month, #1,176 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 5 - Production/StableIntended Audience :: DevelopersIntended Audience :: System AdministratorsLicense :: OSI Approved :: BSD LicenseProgramming Language :: PythonProgramming Language :: Python :: 3Programming Language :: Python :: 3 :: OnlyTopic :: Internet :: Log AnalysisTopic :: Software Development :: Libraries :: Python ModulesTopic :: System :: LoggingTopic :: Utilities |
Evidence: jsonlines-4.0.0-py3-none-any.whl
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