Registry / serialization / yamlordereddictloader

yamlordereddictloader

library0.4.2pypypi✓ verified 84d ago

This module provides a loader and a dumper for PyYAML, enabling the preservation of key order when loading YAML files into `collections.OrderedDict` objects and managing `OrderedDict` objects when dumping to YAML. It is built upon PyYAML and is currently marked as deprecated by its maintainers in favor of `Phynix/yamlloader`.

serialization

pip install yamlordereddictloader

github ↗package ↗

INSTALL

IMPORT

SIG · YAMLORDEREDDICTLOA

yamlordereddictloader

serializationpythonv0.4.2

Install

1.7s avg

Import

132ms

Disk

18MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v0.4.2 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.920 runs

installs and imports cleanly · install 0.0s · import 0.133s · 19.9MB

glibc

py 3.10–3.920 runs

installs and imports cleanly · install 1.7s · import 0.132s · 21MB

18MB installed

● package 18MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

Loader

✓ from yamlordereddictloader import Loader

SafeLoader

✓ from yamlordereddictloader import SafeLoader

Dumper

✓ from yamlordereddictloader import Dumper

SafeDumper

✓ from yamlordereddictloader import SafeDumper

✗ from yamlordereddictloader import CLoader

CLoader and CDumper are specific to `Phynix/yamlloader` for C-accelerated versions, not `yamlordereddictloader`.

OrderedDict

✓ from collections import OrderedDict

Required for creating ordered dictionaries to dump.

This quickstart demonstrates how to load a YAML string into a `collections.OrderedDict` using `SafeLoader` and dump a `collections.OrderedDict` back to a YAML string using `SafeDumper`, preserving key order in both operations.

import yaml from collections import OrderedDict from yamlordereddictloader import SafeLoader, SafeDumper # Create a YAML string with a specific order ordered_data_str = """ key_c: 3 key_a: 1 key_b: 2 inner_dict: inner_b: 'val_b' inner_a: 'val_a' """ # --- Loading YAML with preserved order --- # Using SafeLoader for security loaded_data = yaml.load(ordered_data_str, Loader=SafeLoader) print("Loaded data (type: ", type(loaded_data), "):") for key, value in loaded_data.items(): print(f" {key}: {value}") assert isinstance(loaded_data, OrderedDict) assert list(loaded_data.keys()) == ['key_c', 'key_a', 'key_b', 'inner_dict'] assert list(loaded_data['inner_dict'].keys()) == ['inner_b', 'inner_a'] print("\n--- Dumping data with preserved order ---") # Create an OrderedDict to dump data_to_dump = OrderedDict([ ('name', 'Alice'), ('age', 30), ('details', OrderedDict([ ('city', 'New York'), ('occupation', 'Engineer') ])) ]) # Using SafeDumper for security and default_flow_style=False for block style dumped_yaml = yaml.dump(data_to_dump, Dumper=SafeDumper, default_flow_style=False) print(dumped_yaml) # Verify order after dumping and re-loading (optional, for testing) re_loaded_data = yaml.load(dumped_yaml, Loader=SafeLoader) assert list(re_loaded_data.keys()) == ['name', 'age', 'details'] assert list(re_loaded_data['details'].keys()) == ['city', 'occupation']

Debug

Known issues

breakingThe `yamlordereddictloader` library is officially deprecated by its maintainer. It is recommended to migrate to the `Phynix/yamlloader` project, which offers an improved version with unit tests, performance enhancements (including C-implementation access), and active development.

fix

Migrate your project to use `Phynix/yamlloader`. Install it with `pip install yamlloader` and update your imports (e.g., `from yamlloader.ordereddict import CLoader, CDumper`).

affects: <=0.4.2

gotchaFor Python 3.7+ and PyYAML 5.1+, standard Python dictionaries preserve insertion order by default. Additionally, PyYAML's `dump` function can accept `sort_keys=False` to prevent alphabetical sorting during dumping. This might reduce or eliminate the need for `yamlordereddictloader` in some use cases, especially for dumping. However, `yamlordereddictloader` explicitly uses `OrderedDict` for loading.

fix

Before using `yamlordereddictloader`, consider if PyYAML's native `dict` order preservation (Python 3.7+) and `sort_keys=False` for `yaml.dump` fulfill your requirements. If explicit `OrderedDict` instantiation is still desired for clarity or compatibility, continue using this library or its recommended successor.

affects: All versions

gotchaUsing `yaml.load()` without specifying `Loader=yamlordereddictloader.SafeLoader` can be a security risk. The default `yaml.UnsafeLoader` (or `yaml.FullLoader` in newer PyYAML versions) can construct arbitrary Python objects, potentially allowing an attacker to execute malicious code if they control the YAML input.

fix

Always use `yaml.load(..., Loader=yamlordereddictloader.SafeLoader)` when loading untrusted YAML content. Similarly, use `yaml.dump(..., Dumper=yamlordereddictloader.SafeDumper)` for dumping.

affects: All versions

gotchaWhen loading YAML with aliased objects, `yamlordereddictloader` might not preserve the mapping order as intuitively expected for merged items. Aliased objects might be placed 'too soon' in the resulting `OrderedDict`.

fix

To correctly preserve order with aliases, you may need to implement a custom `flatten_mapping` method by subclassing `yamlordereddictloader.Loader` or consider structuring your YAML to avoid complex aliasing if strict order is paramount. Refer to advanced PyYAML customization for complex scenarios.

affects: All versions

Errors

Common errors & fixes

AttributeError: module 'yamlordereddictloader' has no attribute 'CLoader'

`CLoader` is specific to the `Phynix/yamlloader` library, not `yamlordereddictloader`.

fix

If you intend to use the C-accelerated loaders, you need to install and import from `Phynix/yamlloader` (e.g., `from yamlloader.ordereddict import CLoader`). If you are using `yamlordereddictloader`, use `Loader` or `SafeLoader` instead.

YAML mapping order not preserved when using alias and yamlordereddictloader loader

Complex YAML structures involving aliases and merges can cause the `OrderedDict` from `yamlordereddictloader` to not retain the exact desired insertion order for merged content.

fix

This often requires overriding the `flatten_mapping` method in a custom loader derived from `yamlordereddictloader.Loader` to precisely control how merged nodes are processed. A simpler fix might be to restructure the YAML or avoid aliases if explicit order is critical for merged blocks.

yaml.representer.RepresenterError: cannot represent an object: <class 'collections.OrderedDict'>

This error typically occurs if you try to `yaml.dump` an `OrderedDict` without using `yamlordereddictloader.Dumper` or `SafeDumper` (or a custom representer). PyYAML's default Dumper doesn't know how to represent `OrderedDict` as a standard mapping while preserving order.

fix

Ensure you are passing `Dumper=yamlordereddictloader.Dumper` or `Dumper=yamlordereddictloader.SafeDumper` to your `yaml.dump()` calls. Also, ensure you have `from collections import OrderedDict` for creating the objects to dump.

Upgrade

Version history

0.4.2latest on PyPI · released Sep 22, 2023

Audit

Dependencies

PyYAMLrequiredCore YAML parsing and dumping functionality relies on PyYAML.

Agent activity

20 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/fmenabe/python-yamlordereddictloader ↗

packagehttps://pypi.org/project/yamlordereddictloader/ ↗