yay 0.0.3

An extensible config file format

yay ain’t YAML

yay is a configuration file format built on top of YAML based on our experience with the ConfigParser extensions buildout uses. It adds overlays (one config file including and extending another) and variables.

Consider a config file that looks something like this:

foo:
    bar:
        baz:
            - 1
            - 2
            - 3
    qux: wibble.wobble
    quux: wobble

goo:
    bar:
        baz:
            - 1
            - 2
            - 3
            - 4
    qux: wibble.cobble
    quux: cobble

hoo:
    bar:
        baz:
            - 1
            - 3
    qux: wibble.yobble
    quux: yobble

With yay, this might look like this:

foo:
    bar:
        baz:
            - 1
            - 2
            - 3
    qux: wibble.{:quux}
    quux: wobble

goo.copy: foo
goo:
    bar:
        baz.append:
            - 4
    quux: cobble

hoo.copy: foo
hoo:
    bar:
        baz.remove:
            - 2
    quux: yobble

Using yay

To load yay config from a string you can use the ‘load’ function:

>>> from yay import load
>>> load("""
... foo:
...     bar: 1
... """)
{"foo": {"bar": 1}}

If you want to load from a URI (file:// and http:// are supported) then use ‘load_uri’:

>>> from yay import load_uri
>>> load_uri("/etc/someconfig.yay")
{"foo": {"bar": 1}}

The return value in both cases is a standard python dictionary.

Changelog for yay

0.0.3 (2011-01-24)

• Egg packaging fixes

0.0.2 (2011-01-24)

• Lots more unittests for expression evaluation and expression parsing

• Drop dependency on OrderedDict

0.0.1

• This is still pre-release, no API or language stability guarantees

• Variable resolving is now done in expression tree without a seperate resolve stage

• Uses pyparsing to parse {foo[bar][@.baz > 5]} type syntax

0.0.0

• This is a pre-alpha release to experiment with what we can and can’t do.

• New PyYAML Loader subclass for getting ordered maps without ugly !!omap markup

• Resolves {} markup within YAML nodes

• Lazily evaluates .copy, .append and .remove instructions