Convert either a given YAML file or a YAML from stdin into Java style properties. Requires click, flatdict & pyyaml.

yaml2properties.py

#!/usr/bin/env python3
import click
import flatdict
import yaml
import sys


class DefaultToStdin(click.Argument):
    def __init__(self, *args, **kwargs):
        kwargs["nargs"] = 1
        kwargs["type"] = click.File("r")
        super().__init__(*args, **kwargs)

    def full_process_value(self, ctx, value):
        return super().process_value(ctx, value or ("-",))


@click.command(
    help=("Convert a YAML to Java properties format"),
)
@click.argument("input_file", cls=DefaultToStdin)
@click.option(
    "--no-values",
    "-n",
    default=False,
    is_flag=True,
    help="Do not print values, only keys",
)
def main(input_file, no_values):
    if not input_file:
        input_file = (sys.stdin,)
    doc = yaml.safe_load(input_file)
    flattened = flatdict.FlatDict(doc, delimiter=".")
    keys = sorted(flattened.keys())
    for key in keys:
        print(key, end="")
        if not no_values:
            print(f" = {flattened[key]}", end="")
        print()


if __name__ == "__main__":
    main()