hifiyaml

A high-fidelity WYSIWYG YAML parser and emitter that preserves exact formatting, including comments, anchors, aliases, blank lines, and indentation.
Check the more detailed User Guide
Check wiki at https://github.com/hifiyaml/hifiyaml/wiki

Installation

pip install hifiyaml

Quick demo

1. Get an example YAML file

Use jedivar.yaml from the RRFSv2 system as an example.

wget https://raw.githubusercontent.com/NOAA-EMC/rrfs-workflow/refs/heads/rrfs-mpas-jedi/parm/jedivar.yaml

2. Load the YAML data and dump a YAML block using a querystr

Write the following statments into test.py:

import hifiyaml as hy
data = hy.load("jedivar.yaml")
querystr = "cost function/background error/components/1"
hy.dump(data, querystr)   # dump to stdout
hy.dump(data, querystr, 'ensbec.yaml')   # dump to the file 'ensbec.yaml'

run cd tests; ./test.sh and then check the output yaml files

NOTE: A querystr is a string describing the path from a unique higher level key (or index if a list) to the destination level key (or index), separated with /.
For the following simple YAML file,

demo:
  configuration:
    suite: YAML
    detail:
      - meaning:
          - Y: Yelling
          - A: At
          - M: My
          - L: Laptop

A query string demo/configuration/detail/0/meaning will return one dictionary item with "meaning" as the key and a list of 4 items as the value, i.e:

- meaning:
    - Y: Yelling
    - A: At
    - M: My
    - L: Laptop

3. Availabe functions.

hifiyaml currently provides the following functions:

load, get, dump, drop, modify, next_pos, get_start_pos, dedent, text_to_yblock, strip_indentations, strip_leading_empty_lines

Testing

pip install pytest
python3 -m pytest tests/test_hifiyaml.py -v

and use the shell-based diff tests:

cd tests; ./test.sh