# -*- mode: python -*-
# Copyright (C) 2016 Niklas Rosenstein
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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# THE SOFTWARE.
''' Utility functions to read options from the environment. '''
__all__ = ['get', 'get_bool']
from craftr import module, environ
[docs]def get(name, default=None, inherit_global=True):
''' Reads an option value from the environment variables.
The option name will be prefixed by the identifier of the
module that is currently executed, eg:
.. code:: python
# craftr_module(test)
from craftr import options, environ
value = options.get('debug', inherit_global=False)
# is equal to
value = environ.get('test.debug')
:param name: The name of the option.
:param default: The default value that is returned if the
option is not set in the environment. If :const:`NotImplemented`
is passed for *default* and the option is not set, a :class:`KeyError`
is raised.
:param inherit_global: If this is True, the option is also
searched globally (ie. *name* without the prefix of the
currently executed module).
:raise KeyError: If *default* is :const:`NotImplemented` and the
option does not exist.
'''
full_name = module.project_name + '.' + name
try:
value = environ[full_name]
except KeyError:
if inherit_global:
try:
value = environ[name]
if not value:
raise KeyError(name)
except KeyError:
if default is NotImplemented:
raise KeyError(name)
value = default
else:
value = default
return value
[docs]def get_bool(name, default=False, inherit_global=True):
''' Read a boolean option. The actual option value is interpreted
as boolean value. Allowed values that are interpreted as correct
boolean values are: ``''``, ``'true'``, ``'false''`, ``'yes'``,
``'no'``, ``'0'`` and ``'1'``
:raise KeyError: If *default* is :const:`NotImplemented` and the option
does not exist.
:raise ValueError: If the option exists but has a value that can not
be interpreted as boolean.
'''
try:
value = get(name, NotImplemented, inherit_global)
except KeyError:
if default is NotImplemented:
raise
return default
value = value.lower().strip()
if value in ('0', 'no', 'false', ''):
return False
elif value in ('1', 'yes', 'true'):
return True
else:
raise ValueError('invalid value for option {!r}: {!r}'.format(name, value))