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Diffstat (limited to 'openstack/common/utils.py')
| -rw-r--r-- | openstack/common/utils.py | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/openstack/common/utils.py b/openstack/common/utils.py new file mode 100644 index 0000000..0d2f89e --- /dev/null +++ b/openstack/common/utils.py @@ -0,0 +1,89 @@ +# vim: tabstop=4 shiftwidth=4 softtabstop=4 + +# Copyright 2011 OpenStack LLC. +# 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 datetime +import sys + +from openstack.common import exception + + +TIME_FORMAT = "%Y-%m-%dT%H:%M:%SZ" + + +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): + """ + Interpret a string as a boolean. + + Any string value in: + ('True', 'true', 'On', 'on', '1') + is interpreted as a boolean True. + + Useful for JSON-decoded stuff and config file parsing + """ + if type(subject) == type(bool): + return subject + if hasattr(subject, 'startswith'): # str or unicode... + if subject.strip().lower() in ('true', 'on', '1'): + return True + return False + + +def import_class(import_str): + """Returns a class from a string including module and class""" + mod_str, _sep, class_str = import_str.rpartition('.') + try: + __import__(mod_str) + return getattr(sys.modules[mod_str], class_str) + except (ImportError, ValueError, AttributeError): + raise exception.NotFound('Class %s cannot be found' % class_str) + + +def import_object(import_str): + """Returns an object including a module or module and class""" + try: + __import__(import_str) + return sys.modules[import_str] + except ImportError: + cls = import_class(import_str) + return cls() + + +def isotime(at=None): + if not at: + at = datetime.datetime.utcnow() + return at.strftime(TIME_FORMAT) + + +def parse_isotime(timestr): + return datetime.datetime.strptime(timestr, TIME_FORMAT) |
