Merge lp:~hopem/charm-helpers/add-core-strutils into lp:charm-helpers

[Edward Hope-Morley]

[lp:~hopem/charm-helpers/add-core-strutils]

309. By Edward Hope-Morley on 2015-02-16

simplified

[Liam Young (gnuoy)]

Approve

review: Approve

=== added file 'charmhelpers/core/strutils.py'
--- charmhelpers/core/strutils.py	1970-01-01 00:00:00 +0000
+++ charmhelpers/core/strutils.py	2015-02-16 11:02:09 +0000
@@ -0,0 +1,38 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Copyright 2014-2015 Canonical Limited.
+#
+# This file is part of charm-helpers.
+#
+# charm-helpers is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License version 3 as
+# published by the Free Software Foundation.
+#
+# charm-helpers is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with charm-helpers.  If not, see <http://www.gnu.org/licenses/>.
+
+
+def bool_from_string(value):
+    """Interpret string value as boolean.
+
+    Returns True if value translates to True otherwise False.
+    """
+    if isinstance(value, str):
+        value = value.lower()
+    else:
+        msg = "Unable to interpret non-string value '%s' as boolean" % (value)
+        raise ValueError(msg)
+
+    if value in ['y', 'yes', 'true', 't']:
+        return True
+    elif value in ['n', 'no', 'false', 'f']:
+        return False
+
+    msg = "Unable to interpret string value '%s' as boolean" % (value)
+    raise ValueError(msg)
 
=== added file 'tests/core/test_strutils.py'
--- tests/core/test_strutils.py	1970-01-01 00:00:00 +0000
+++ tests/core/test_strutils.py	2015-02-16 11:02:09 +0000
@@ -0,0 +1,29 @@
+import unittest
+
+import charmhelpers.core.strutils as strutils
+
+
+class TestStrUtils(unittest.TestCase):
+    def setUp(self):
+        super(TestStrUtils, self).setUp()
+
+    def tearDown(self):
+        super(TestStrUtils, self).tearDown()
+
+    def test_bool_from_string(self):
+        self.assertTrue(strutils.bool_from_string('true'))
+        self.assertTrue(strutils.bool_from_string('True'))
+        self.assertTrue(strutils.bool_from_string('yes'))
+        self.assertTrue(strutils.bool_from_string('Yes'))
+        self.assertTrue(strutils.bool_from_string('y'))
+        self.assertTrue(strutils.bool_from_string('Y'))
+
+        self.assertFalse(strutils.bool_from_string('False'))
+        self.assertFalse(strutils.bool_from_string('false'))
+        self.assertFalse(strutils.bool_from_string('no'))
+        self.assertFalse(strutils.bool_from_string('No'))
+        self.assertFalse(strutils.bool_from_string('n'))
+        self.assertFalse(strutils.bool_from_string('N'))
+
+        self.assertRaises(ValueError, strutils.bool_from_string, None)
+        self.assertRaises(ValueError, strutils.bool_from_string, 'foo')