~james-page/charms/trusty/odl-controller/doc-updates

1 by Robert Ayres
Initial charm
1
#!/usr/bin/env python
2
# -*- coding: utf-8 -*-
3
4
# Copyright 2014-2015 Canonical Limited.
5
#
6
# This file is part of charm-helpers.
7
#
8
# charm-helpers is free software: you can redistribute it and/or modify
9
# it under the terms of the GNU Lesser General Public License version 3 as
10
# published by the Free Software Foundation.
11
#
12
# charm-helpers is distributed in the hope that it will be useful,
13
# but WITHOUT ANY WARRANTY; without even the implied warranty of
14
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15
# GNU Lesser General Public License for more details.
16
#
17
# You should have received a copy of the GNU Lesser General Public License
18
# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
19
20
import six
21
22
23
def bool_from_string(value):
24
    """Interpret string value as boolean.
25
26
    Returns True if value translates to True otherwise False.
27
    """
28
    if isinstance(value, six.string_types):
29
        value = six.text_type(value)
30
    else:
31
        msg = "Unable to interpret non-string value '%s' as boolean" % (value)
32
        raise ValueError(msg)
33
34
    value = value.strip().lower()
35
6 by Liam Young
Charmhelper sync
36
    if value in ['y', 'yes', 'true', 't', 'on']:
1 by Robert Ayres
Initial charm
37
        return True
6 by Liam Young
Charmhelper sync
38
    elif value in ['n', 'no', 'false', 'f', 'off']:
1 by Robert Ayres
Initial charm
39
        return False
40
41
    msg = "Unable to interpret string value '%s' as boolean" % (value)
42
    raise ValueError(msg)