yamlreader 3

Merge YAML data from given files, dir or file glob

Merge YAML data from a directory, a list of files or a file glob. With a directory, the YAML files (*.yaml) are sorted alphabetically. The YAML files are expected to contain a complex key-value structure and merged with the following rules:

• lists get appended

• hashes get merged by key

• scalars (numbers, strings) are overwritten

• everything else will fail

The purpose is to allow several YAML files instead of a single YAML file. We use it to help our software read configuration data from an arbitrary amount of YAML files instead of a single YAML file.

Read the unit test to see some examples.

Building

1. Check out the source

2. Build a package

1. RPM: Run python setup.py clean bdist_rpm, results will be in dist/

2. DEB: Install python-stdeb and run python setup.py –command-packages=stdeb.command clean bdist_deb, results will be in deb_dist

Running

The package installs a command line script yamlreader that can be used to read one or many YAML files and dump the merge result as a YAML document.

Contributing

Create a new virtual environment:

virtualenv venv

Activate the virtual environment:

source venv/bin/activate

Install requirements using pip:

pip install -r requirements.txt

Now you are able to run the tests:

python setup.py test

Use it in your software

Wherever you had been using the safe_load function of PyYAML to read a single YAML file you can use the yamlreader.yaml_load function as a replacement to read all *.yaml files in a directory:

from yamlreader import *

defaultconfig = {
        "loglevel" : "error",
        "some" : "value"
}

config = yaml_load("/etc/myapp", defaultconfig)

load_yaml

def yaml_load(source,defaultdata=None):
    """merge YAML data from files found in source

    Always returns a dict. The YAML files are expected to contain some kind of
    key:value structures, possibly deeply nested. When merging, lists are
    appended and dict keys are replaced. The YAML files are read with the
    yaml.safe_load function.

    source can be a file, a dir, a list/tuple of files or a string containing
    a glob expression (with ?*[]).

    For a dir all *.yaml files will be read in alphabetical order.

    defaultdata can be used to initialize the data.
    """