ryaml

Quickly and safely parse yaml

What is ryaml?

ryaml is a Python library that wraps a Rust yaml parser, serde-yaml, to quickly and safely parse and dump yaml to and from Python objects.

It is not compatible with PyYAML, but has a similar design to the json module.

The hope is this will be used as a safe and fast yaml parser in lieu of PyYAML.

Installation

We ship binary wheels for Windows, Linux, and macOS, so as long as you are using Python 3.7+, you can run:

$ python -m pip install ryaml

Otherwise, you will need to build from source. To do so, first install Rust 1.41 stable.

Then you should be able to just

$ git clone https://github.com/ethanhs/ryaml
$ cd ryaml
$ python -m pip install .

Or if you want to build a wheel:

$ git clone https://github.com/ethanhs/ryaml
$ cd ryaml
$ python -m pip install maturin
$ maturin build --release --no-sdist
# OR if you want an abi3 wheel (compatible with Python 3.7+)
$ maturin build --release --no-sdist --cargo-extra-args="--features=abi3"

And a wheel will be created in target/wheels which you can install.

Usage

The API of ryaml is very similar to that of json in the standard library:

You can use ryaml.loads to read from a str:

import ryaml
obj = ryaml.loads('key: [10, "hi"]')
assert isinstance(obj, dict) # True
assert obj['key'][1] == "hi" # True

And ryaml.dumps to dump an object into a yaml file:

import ryaml
s = ryaml.dumps({ 'key' : None })
print(s)
# prints:
# ---
# key: ~

There are also ryaml.load and ryaml.load_all to read yaml document(s) from files:

import ryaml
obj = {'a': [{'b': 1}]}
with open('test.yaml', 'w') as w:
    ryaml.dump(w, obj)
with open('test.yaml', 'r') as r:
    assert ryaml.load(r) == obj
with open('multidoc.yaml', 'w') as multi:
    multi.write('''
---
a:
  key:
...
---
b:
  key:
    ''')
with open('multidoc.yaml', 'r') as multi:
    docs = ryaml.load_all(multi)
assert len(docs) == 2
assert docs[0]['a']['key'] is None

ryaml.load_all will, as seen above, load multiple documents from a single file.

Thanks

This project is standing on the shoulders of giants, and would not be possible without:

pyo3

serde-yaml

yaml-rust

pyo3-file

pythonize