Package: tweak
Tweak is a Python helper class to ingest and serialize app-specific configuration.Tweak provides a self-contained (no dependencies outside the standard library), Python 2 and 3 compatible configuration
manager. It automatically saves and restores your application’s configuration in your user home directory. It uses JSON or
(optionally) YAML for serialization. It supports dict-like methods and access semantics, hierarchical configuration sources,
and array merge operators for layering configuration options (see below).InstallationIf your package does not permit dependency management, you can copy theConfigclass directly into your
application fromhttps://github.com/kislyuk/tweak/blob/master/tweak/__init__.py. Otherwise:pip install tweakSynopsisfromtweakimportConfigconfig=Config()config.host,config.port="example.com",9000config.nested_config={}config.nested_config.foo=TrueAfter restarting your application:config = Config()
print(config)
>>> {'host': 'example.com', 'port': 9000, 'nested_config': {'foo': True}}Using anargparse.Namespaceobject returned byargparse.parse_args():parser = argparse.ArgumentParser()
...
args = parser.parse_args()
if args.foo is not None:
    config.foo = args.foo
elif "foo" not in config:
    raise Exception("foo unconfigured")

config.update(vars(args))Using YAML:config = Config(use_yaml=True)
...PassConfig(save_on_exit=False)to disable automatic configuration saving on Python shutdown (this is useful if you
only want to read the config, never write it, or if you want to callconfig.save()manually). PassConfig(autosave=True)to makesave()run any time an assignment happens to a config object.Configuration ingestion orderTweak supports ingesting configuration from a configurable array of sources. Each source is a JSON or YAML file.
Configuration sources that follow the first source update the configuration using recursive dictionary merging. Sources are
enumerated in the following order:Site-wide configuration source,/etc/NAME/config.(yml|json)User configuration source,~/.config/NAME/config.(yml|json)Any sources listed in the colon-delimited variableNAME_CONFIG_FILEArray merge operatorsWhen loading a chain of configuration sources, Tweak uses recursive dictionary merging to combine the
sources. Additionally, when the original config value is a list, Tweak supports array manipulation operators:In [1]: from tweak import Config

In [2]: c = Config()

In [3]: c.update(x=[1, 2, 3])

In [4]: c
Out[4]: {'x': [1, 2, 3]}

In [5]: c.update(x={"$append": 4})

In [6]: c
Out[6]: {'x': [1, 2, 3, 4]}

In [7]: c.update(x={"$extend": [5, 6]})

In [8]: c
Out[8]: {'x': [1, 2, 3, 4, 5, 6]}

In [9]: c.update(x={"$insert": {0: 0}})

In [10]: c
Out[10]: {'x': [0, 1, 2, 3, 4, 5, 6]}

In [11]: c.update(x={"$extendleft": [-2, -1]})

In [12]: c
Out[12]: {'x': [-2, -1, 0, 1, 2, 3, 4, 5, 6]}

In [13]: c.update(x={"$remove": 0})

In [14]: c
Out[14]: {'x': [-2, -1, 1, 2, 3, 4, 5, 6]}Each operator ($append,$extend,$insert,$extendleft,$remove) must be the only key in the
dictionary representing the update, and the value being updated must be a list. For example, in the following set of two
YAML files, the second file extends the list in the first file./etc/NAME/config.yml:x:
 - y
 - z~/.config/NAME/config.yml:x:
 $extend:
   - a
   - bInclude directivesThe optionalConfig(allow_includes=True)keyword argument can be used to trigger processing of include directives in
config files. For each config source file ingested, a top levelincludekey can contain a string or array of
strings. Each of these strings will be globbed and ingested before the file contianing the directive (e.g.{"include":"config.d/*"}to ingest a directory of config files).AuthorsAndrey KislyukLinksProject home page (GitHub)Documentation (Read the Docs)Package distribution (PyPI)BugsPlease report bugs, issues, feature requests, etc. onGitHub.LicenseLicensed under the terms of theApache License, Version 2.0.