yamlloader
Ordered YAML loader and dumper for PyYAML.
Decision gist · record as of 2026-08-14
Yes. yamlloader is a mature, actively maintained library with no known vulnerabilities, low install friction, and a permissive MIT license. Install it if your workflow requires YAML key order preservation; the automatic C fallback makes it safe across environments. Skip it if you don't care about key ordering or are already using a different ordered YAML solution.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- C version requires libyaml-dev (system library) and Cython for compilation; pure Python fallback is automatic if C extensions unavailable.
- Low friction: single runtime dependency on pyyaml, pure Python wheel available.
- Actively maintained with recent release; C extensions fall back gracefully to pure Python if unavailable, making installation safe across environments.
License · maintenance · safety
permissive license (permissive) — MIT license (permissive). Dual-licensed code includes original work by Jonas Eschle and portions from François Ménabé, both under MIT terms. No restrictions on commercial or private use.
last release 2025-11-10 (277 days) · last repo commit 2026-08-01 · 9 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 294,389 downloads/mo, #7,947 on PyPI
Alternatives
Verify before relying
import yamlloader
import pyyaml
with open('myfile.yml') as yaml_file:
data = pyyaml.load(yaml_file, Loader=yamlloader.ordereddict.CLoader)- Whether C extension compilation is reliable across all target Python versions (3.8–3.14) and platforms in typical CI/CD environments.
- Performance gains from C versions relative to pure Python in real-world YAML file sizes and workloads.
- Specific performance improvement magnitude from C-accelerated Loader/Dumper classes versus pure Python versions.
What it is and what it does
yamlloader extends pyyaml with specialized loaders and dumpers that maintain insertion order when reading and writing YAML files. Since Python 3.7+, regular dicts preserve insertion order as a language feature, and yamlloader leverages this to ensure YAML key order is not lost during serialization and deserialization. The package offers both pure Python and C-accelerated implementations; the C versions are optional—if pyyaml's C extensions are not compiled, yamlloader automatically falls back to pure Python.
The library is designed for workflows where YAML file structure and key ordering matter: configuration files, data interchange, and any scenario where round-tripping YAML through Python objects must preserve the original layout. It depends only on pyyaml and has no other runtime dependencies, making it lightweight to add to existing projects.
Use it for
- Loading configuration files where key order in YAML reflects priority or logical grouping that must be preserved.
- Round-tripping YAML documents: load, modify in Python, dump back with original key order intact.
- Data serialization workflows requiring deterministic YAML output order for version control or diff readability.
- Scientific or administrative tools that consume structured YAML and need to maintain human-readable key ordering.
- Building YAML-based data pipelines where consistent ordering aids debugging and reproducibility.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes.
yamlloader is a mature, actively maintained library with no known vulnerabilities, low install friction, and a permissive MIT license. Install it if your workflow requires YAML key order preservation; the automatic C fallback makes it safe across environments. Skip it if you don't care about key ordering or are already using a different ordered YAML solution.
Install
yamlloader on PyPI
Before you install
Low friction: single runtime dependency on pyyaml, pure Python wheel available. Actively maintained with recent release; C extensions fall back gracefully to pure Python if unavailable, making installation safe across environments.
C version requires libyaml-dev (system library) and Cython for compilation; pure Python fallback is automatic if C extensions unavailable.
License in practice
MIT license (permissive). Dual-licensed code includes original work by Jonas Eschle and portions from François Ménabé, both under MIT terms. No restrictions on commercial or private use.
Quickstart
import yamlloader
import pyyaml
with open('myfile.yml') as yaml_file:
data = pyyaml.load(yaml_file, Loader=yamlloader.ordereddict.CLoader)Verify before relying
- Whether C extension compilation is reliable across all target Python versions (3.8–3.14) and platforms in typical CI/CD environments.
- Performance gains from C versions relative to pure Python in real-world YAML file sizes and workloads.
- Specific performance improvement magnitude from C-accelerated Loader/Dumper classes versus pure Python versions.
Package facts
| License | permissive license permissive |
| Python support | Supports the current Python release >=3.8 |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | 1 packagepyyaml |
| Maintenance | Actively maintained 277 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 294,389 / month, #7,947 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 :: Science/ResearchIntended Audience :: System AdministratorsLicense :: OSI Approved :: MIT LicenseNatural Language :: EnglishProgramming Language :: PythonProgramming Language :: Python :: 3 :: OnlyProgramming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Programming Language :: Python :: 3.14Programming Language :: Python :: 3.8Programming Language :: Python :: 3.9Topic :: Software Development :: LibrariesTopic :: Utilities |
Evidence: yamlloader-1.6.0-py3-none-any.whl
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See also aspy.yaml · yamlordereddictloader · oyaml · poyo · HiYaPyCo · yamlcore · keynote-parser · ordereddict · saneyaml · PyYAML-ft