From 1b9489fb0d556a2661c299cf67ed3d26ffcb2dce Mon Sep 17 00:00:00 2001 From: Rick Harris Date: Thu, 9 May 2013 22:39:20 +0000 Subject: Use Oslo's `bool_from_string` Oslo provides an equivalent implmentation of `bool_from_str` so we should switch the code to use that instead. Change-Id: I382f23af2468e276ae4342dff18cf06e1c24b755 --- nova/openstack/common/strutils.py | 150 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 150 insertions(+) create mode 100644 nova/openstack/common/strutils.py (limited to 'nova/openstack') diff --git a/nova/openstack/common/strutils.py b/nova/openstack/common/strutils.py new file mode 100644 index 000000000..cdf70cb20 --- /dev/null +++ b/nova/openstack/common/strutils.py @@ -0,0 +1,150 @@ +# vim: tabstop=4 shiftwidth=4 softtabstop=4 + +# Copyright 2011 OpenStack Foundation. +# All Rights Reserved. +# +# Licensed under the Apache License, Version 2.0 (the "License"); you may +# not use this file except in compliance with the License. You may obtain +# a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT +# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the +# License for the specific language governing permissions and limitations +# under the License. + +""" +System-level utilities and helper functions. +""" + +import sys + +from nova.openstack.common.gettextutils import _ + + +TRUE_STRINGS = ('1', 't', 'true', 'on', 'y', 'yes') +FALSE_STRINGS = ('0', 'f', 'false', 'off', 'n', 'no') + + +def int_from_bool_as_string(subject): + """ + Interpret a string as a boolean and return either 1 or 0. + + Any string value in: + + ('True', 'true', 'On', 'on', '1') + + is interpreted as a boolean True. + + Useful for JSON-decoded stuff and config file parsing + """ + return bool_from_string(subject) and 1 or 0 + + +def bool_from_string(subject, strict=False): + """ + Interpret a string as a boolean. + + A case-insensitive match is performed such that strings matching 't', + 'true', 'on', 'y', 'yes', or '1' are considered True and, when + `strict=False`, anything else is considered False. + + Useful for JSON-decoded stuff and config file parsing. + + If `strict=True`, unrecognized values, including None, will raise a + ValueError which is useful when parsing values passed in from an API call. + Strings yielding False are 'f', 'false', 'off', 'n', 'no', or '0'. + """ + if not isinstance(subject, basestring): + subject = str(subject) + + lowered = subject.strip().lower() + + if lowered in TRUE_STRINGS: + return True + elif lowered in FALSE_STRINGS: + return False + elif strict: + acceptable = ', '.join( + "'%s'" % s for s in sorted(TRUE_STRINGS + FALSE_STRINGS)) + msg = _("Unrecognized value '%(val)s', acceptable values are:" + " %(acceptable)s") % {'val': subject, + 'acceptable': acceptable} + raise ValueError(msg) + else: + return False + + +def safe_decode(text, incoming=None, errors='strict'): + """ + Decodes incoming str using `incoming` if they're + not already unicode. + + :param incoming: Text's current encoding + :param errors: Errors handling policy. See here for valid + values http://docs.python.org/2/library/codecs.html + :returns: text or a unicode `incoming` encoded + representation of it. + :raises TypeError: If text is not an isntance of basestring + """ + if not isinstance(text, basestring): + raise TypeError("%s can't be decoded" % type(text)) + + if isinstance(text, unicode): + return text + + if not incoming: + incoming = (sys.stdin.encoding or + sys.getdefaultencoding()) + + try: + return text.decode(incoming, errors) + except UnicodeDecodeError: + # Note(flaper87) If we get here, it means that + # sys.stdin.encoding / sys.getdefaultencoding + # didn't return a suitable encoding to decode + # text. This happens mostly when global LANG + # var is not set correctly and there's no + # default encoding. In this case, most likely + # python will use ASCII or ANSI encoders as + # default encodings but they won't be capable + # of decoding non-ASCII characters. + # + # Also, UTF-8 is being used since it's an ASCII + # extension. + return text.decode('utf-8', errors) + + +def safe_encode(text, incoming=None, + encoding='utf-8', errors='strict'): + """ + Encodes incoming str/unicode using `encoding`. If + incoming is not specified, text is expected to + be encoded with current python's default encoding. + (`sys.getdefaultencoding`) + + :param incoming: Text's current encoding + :param encoding: Expected encoding for text (Default UTF-8) + :param errors: Errors handling policy. See here for valid + values http://docs.python.org/2/library/codecs.html + :returns: text or a bytestring `encoding` encoded + representation of it. + :raises TypeError: If text is not an isntance of basestring + """ + if not isinstance(text, basestring): + raise TypeError("%s can't be encoded" % type(text)) + + if not incoming: + incoming = (sys.stdin.encoding or + sys.getdefaultencoding()) + + if isinstance(text, unicode): + return text.encode(encoding, errors) + elif text and encoding != incoming: + # Decode text before encoding it with `encoding` + text = safe_decode(text, incoming, errors) + return text.encode(encoding, errors) + + return text -- cgit