71 lines
2 KiB
Python
71 lines
2 KiB
Python
import io
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import ruamel.yaml
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def set_values(config, keys, value):
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'''
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Given a hierarchy of configuration dicts, a sequence of parsed key strings, and a string value,
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descend into the hierarchy based on the keys to set the value into the right place.
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'''
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if not keys:
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return
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first_key = keys[0]
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if len(keys) == 1:
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config[first_key] = value
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return
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if first_key not in config:
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config[first_key] = {}
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set_values(config[first_key], keys[1:], value)
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def convert_value_type(value):
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'''
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Given a string value, determine its logical type (string, boolean, integer, etc.), and return it
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converted to that type.
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'''
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return ruamel.yaml.YAML(typ='safe').load(io.StringIO(value))
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def parse_overrides(raw_overrides):
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'''
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Given a sequence of configuration file override strings in the form of "section.option=value",
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parse and return a sequence of tuples (keys, values), where keys is a sequence of strings. For
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instance, given the following raw overrides:
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['section.my_option=value1', 'section.other_option=value2']
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... return this:
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(
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(('section', 'my_option'), 'value1'),
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(('section', 'other_option'), 'value2'),
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)
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Raise ValueError if an override can't be parsed.
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'''
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if not raw_overrides:
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return ()
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try:
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return tuple(
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(tuple(raw_keys.split('.')), convert_value_type(value))
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for raw_override in raw_overrides
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for raw_keys, value in (raw_override.split('=', 1),)
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)
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except ValueError:
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raise ValueError('Invalid override. Make sure you use the form: SECTION.OPTION=VALUE')
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def apply_overrides(config, raw_overrides):
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'''
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Given a sequence of configuration file override strings in the form of "section.option=value"
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and a configuration dict, parse each override and set it the configuration dict.
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'''
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overrides = parse_overrides(raw_overrides)
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for (keys, value) in overrides:
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set_values(config, keys, value)
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