orxml 0.1.0

Rust-backed xmltodict-compatible XML parser/emitter with PyO3 bindings

orxml

Rust-backed XML ↔ Python dict conversion, API-compatible with the common surface of [xmltodict](https://github.com/martinblech/xmltodict). 3–8× faster on a representative corpus.

Uses the BadgerFish-lite convention: @ prefix for attributes, #text for text content, lists for repeated sibling elements. Because the shape is JSON-compatible, any parsed dict feeds straight into json.dumps.

Install (from source)

git clone https://github.com/bohdanhr/orxml
cd orxml
uv sync
uv run maturin develop --release

Requires a stable Rust toolchain and Python 3.11+.

Usage

import orxml

doc = orxml.parse("<a prop='x'>hello</a>")
# {'a': {'@prop': 'x', '#text': 'hello'}}

xml = orxml.unparse(doc)

Supported options

parse: attr_prefix, cdata_key, force_cdata (bool / tuple / list), cdata_separator, strip_whitespace, namespace_separator, process_namespaces, namespaces, process_comments, comment_key, force_list (bool / tuple / list), disable_entities, xml_attribs.

unparse: attr_prefix, cdata_key, comment_key, namespaces, namespace_separator, pretty, newl, indent (str or int), full_document, short_empty_elements, encoding.

Out-of-scope options (postprocessor, item_callback / item_depth streaming, callable force_list / force_cdata, dict_constructor, preprocessor, expand_iter, file-like / generator inputs) raise NotImplementedError if passed. Unknown options raise TypeError.

Parity

Behavior is matched on the observable surface: for every supported option combination, orxml.parse(xml) == xmltodict.parse(xml) and xmltodict.parse(orxml.unparse(d)) == d. Intentional divergences:

• Exception classes: orxml.ParseError (a ValueError), not xml.parsers.expat.ExpatError.
• Error messages and byte-level unparse output (e.g. attribute ordering) are not guaranteed identical.
• Behavior on malformed XML is not defined.

Benchmarks

Run on an Apple Silicon laptop comparing orxml against xmltodict 0.14:

Operation	Fixture	orxml (mean)	xmltodict (mean)	Speedup
parse	tiny.xml	3.55 µs	14.43 µs	4.07×
parse	small.xml	33.56 µs	119.78 µs	3.57×
parse	rss.xml	36.94 µs	131.46 µs	3.56×
parse	soap.xml	30.11 µs	134.53 µs	4.47×
parse	large_synthetic.xml	51.20 ms	162.10 ms	3.17×
unparse	tiny.xml	2.56 µs	11.53 µs	4.51×
unparse	small.xml	25.28 µs	108.40 µs	4.29×
unparse	rss.xml	27.67 µs	112.74 µs	4.07×
unparse	soap.xml	18.52 µs	88.06 µs	4.75×
unparse	large_synthetic.xml	33.17 ms	257.12 ms	7.75×

Reproduce locally with make bench.

Development

make sync        # uv sync
make build       # maturin develop --release
make test        # pytest
make bench       # pytest-benchmark
make lint        # ruff check
make fmt         # ruff format
make typecheck   # ty check
make all         # sync + build + lint + typecheck + test

Corpus

bench/corpus/ holds fixtures used by both tests and benchmarks: tiny.xml, small.xml, rss.xml, soap.xml, and large_synthetic.xml. The last one is generated — regenerate it (or resize it) with:

uv run python bench/corpus/generate_large.py 5000   # ~3 MB

License

MIT