yaml-rs

0.1.0 verified Sat May 09 auth: no python

A high-performance YAML parser for Python written in Rust. Current version 0.1.0. Uses the saphyr YAML library under the hood. Provides loads/dumps with a DuplicateKeyPolicy enum (default Error). Active development, weekly releases.

pip install yaml-rs

Common errors

error yaml_rs.YAMLDecodeError: Duplicate key found: x ↓

cause Default behavior in 0.1.0+ is to error on duplicate keys. Previous versions allowed overwriting.

fix

Use DuplicateKeyPolicy.LastWins: loads(yaml, duplicate_key_policy=DuplicateKeyPolicy.LastWins)

error ModuleNotFoundError: No module named 'yaml_rs' ↓

cause Package not installed or wrong Python environment.

fix

Run pip install yaml-rs and ensure you're using the correct interpreter (Python >=3.10).

Warnings

breaking In version 0.1.0, the default DuplicateKeyPolicy changed from 'LastWins' to 'Error'. Parsing YAML with duplicate keys will now raise YAMLDecodeError instead of silently using the last value. ↓

fix To preserve old behavior, pass DuplicateKeyPolicy.LastWins: loads(yaml_str, duplicate_key_policy=DuplicateKeyPolicy.LastWins)

gotcha yaml-rs does not support all YAML 1.2 features. It is based on the saphyr crate which targets YAML 1.1. Some edge cases may parse differently than PyYAML. ↓

fix Test your YAML data thoroughly. Use strict YAML 1.1 compliant documents.

deprecated No deprecations known at this time.

Imports

loads
wrong
```
import yaml_rs
 yaml_rs.loads(yaml)
```
correct
```
from yaml_rs import loads
```
Not wrong functionally, but direct import is idiomatic.
dumps
```
from yaml_rs import dumps
```
YAMLDecodeError
wrong
```
yaml_rs.YAMLDecodeError
```
correct
```
from yaml_rs import YAMLDecodeError
```
Works but direct import is cleaner.
DuplicateKeyPolicy
```
from yaml_rs import DuplicateKeyPolicy
```

Quickstart

Quick example of dumping and loading YAML with yaml-rs.

from yaml_rs import loads, dumps

data = {"name": "yaml-rs", "version": [0, 1, 0]}
yaml_str = dumps(data)
print(yaml_str)
# 'name: yaml-rs\nversion: [0, 1, 0]\n'

parsed = loads(yaml_str)
print(parsed)
# {'name': 'yaml-rs', 'version': [0, 1, 0]}