diff --git a/confuse.py b/confuse.py index a9c2f96..0460499 100644 --- a/confuse.py +++ b/confuse.py @@ -17,6 +17,8 @@ """ from __future__ import division, absolute_import, print_function +import argparse +import optparse import platform import os import pkgutil @@ -60,6 +62,21 @@ def iter_first(sequence): raise ValueError() +def namespace_to_dict(obj): + """If obj is argparse.Namespace or optparse.Values we'll return + a dict representation of it, else return the original object. + + Redefine this method if using other parsers. + + :param obj: * + :return: + :rtype: dict or * + """ + if isinstance(obj, (argparse.Namespace, optparse.Values)): + return vars(obj) + return obj + + # Exceptions. class ConfigError(Exception): @@ -243,15 +260,86 @@ class ConfigView(object): def __contains__(self, key): return self[key].exists() - def set_args(self, namespace): + @classmethod + def _build_namespace_dict(cls, obj, dots=False): + """Recursively replaces all argparse.Namespace and optparse.Values + with dicts and drops any keys with None values. + + Additionally, if dots is True, will expand any dot delimited + keys. + + :param obj: Namespace, Values, or dict to iterate over. Other + values will simply be returned. + :type obj: argparse.Namespace or optparse.Values or dict or * + :param dots: If True, any properties on obj that contain dots (.) + will be broken down into child dictionaries. + :return: A new dictionary or the value passed if obj was not a + dict, Namespace, or Values. + :rtype: dict or * + """ + # We expect our root object to be a dict, but it may come in as + # a namespace + obj = namespace_to_dict(obj) + # We only deal with dictionaries + if not isinstance(obj, dict): + return obj + + # Get keys iterator + keys = obj.keys() if PY3 else obj.iterkeys() + if dots: + # Dots needs sorted keys to prevent parents from + # clobbering children + keys = sorted(list(keys)) + + output = {} + for key in keys: + value = obj[key] + if value is None: # Avoid unset options. + continue + + save_to = output + result = cls._build_namespace_dict(value, dots) + if dots: + # Split keys by dots as this signifies nesting + split = key.split('.') + if len(split) > 1: + # The last index will be the key we assign result to + key = split.pop() + # Build the dict tree if needed and change where + # we're saving to + for child_key in split: + if child_key in save_to and \ + isinstance(save_to[child_key], dict): + save_to = save_to[child_key] + else: + # Clobber or create + save_to[child_key] = {} + save_to = save_to[child_key] + + # Save + if key in save_to: + save_to[key].update(result) + else: + save_to[key] = result + return output + + def set_args(self, namespace, dots=False): """Overlay parsed command-line arguments, generated by a library like argparse or optparse, onto this view's value. + + :param namespace: Dictionary or Namespace to overlay this config with. + Supports nested Dictionaries and Namespaces. + :type namespace: dict or Namespace + :param dots: If True, any properties on namespace that contain dots (.) + will be broken down into child dictionaries. + :Example: + + {'foo.bar': 'car'} + # Will be turned into + {'foo': {'bar': 'car'}} + :type dots: bool """ - args = {} - for key, value in namespace.__dict__.items(): - if value is not None: # Avoid unset options. - args[key] = value - self.set(args) + self.set(self._build_namespace_dict(namespace, dots)) # Magical conversions. These special methods make it possible to use # View objects somewhat transparently in certain circumstances. For diff --git a/docs/index.rst b/docs/index.rst index c900a37..a3c7e14 100644 --- a/docs/index.rst +++ b/docs/index.rst @@ -167,6 +167,24 @@ consider this argparse script:: This will allow the user to override the configured value for key ``foo`` by passing ``--foo `` on the command line. +Overriding nested values can be accomplished by passing `dots=True` and +have dot-delimited properties on the incoming object.:: + + parser.add_argument('--bar', help='nested parameter', dest='foo.bar') + args = parser.parse_args() # args looks like: {'foo.bar': 'value'} + config.set_args(args, dots=True) + print(config['foo']['bar'].get()) + +`parse_args` works with generic dictionaries too.:: + + args = { + 'foo': { + 'bar': 1 + } + } + config.set_args(args, dots=True) + print(config['foo']['bar'].get()) + .. _argparse: http://docs.python.org/dev/library/argparse.html .. _parse_args: http://docs.python.org/library/argparse.html#the-parse-args-method .. _optparse: http://docs.python.org/library/optparse.html diff --git a/example/__init__.py b/example/__init__.py index 0717181..33b4306 100644 --- a/example/__init__.py +++ b/example/__init__.py @@ -23,7 +23,7 @@ def main(): parser = argparse.ArgumentParser(description='example Confuse program') parser.add_argument('--library', '-l', dest='library', metavar='LIBPATH', help='library database file') - parser.add_argument('--directory', '-d', dest='directory', + parser.add_argument('--directory', '-d', dest='paths.directory', metavar='DIRECTORY', help='destination music directory') parser.add_argument('--verbose', '-v', dest='verbose', action='store_true',