New module with handy method to format using ICU library.

__init__.py

+from .icuformat import icuformat  # noqa: F401

__manifest__.py

+##############################################################################
+#
+#    Copyright (C) 2019 XCG Consulting <http://odoo.consulting>
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU Affero General Public License as
+#    published by the Free Software Foundation, either version 3 of the
+#    License, or (at your option) any later version.
+#
+#    This program 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 Affero General Public License for more details.
+#
+#    You should have received a copy of the GNU Affero General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+##############################################################################
+
+{
+    'name': 'ICU Format',
+    'summary': 'Format message using ICU',
+    'version': '11.0.0.1',
+    'category': 'Technical',
+    'author': 'XCG Consulting',
+    'website': 'http://odoo.consulting/',
+    'license': 'AGPL-3',
+    'depends': [
+        'base',
+    ],
+    'external_dependencies': {
+        'python': [
+            'PyICU',
+        ],
+    },
+    'installable': True,
+}

icuformat.py

+##############################################################################
+#
+#    Copyright (C) 2019 XCG Consulting <http://odoo.consulting>
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU Affero General Public License as
+#    published by the Free Software Foundation, either version 3 of the
+#    License, or (at your option) any later version.
+#
+#    This program 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 Affero General Public License for more details.
+#
+#    You should have received a copy of the GNU Affero General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+##############################################################################
+from typing import Dict, Union
+
+from icu import Formattable, Locale, MessageFormat
+
+
+def icuformat(lang, msg: str, args: Dict[str, Union[int, str]]) -> str:
+    key_list = list()
+    value_list = list()
+    for key, value in args.items():
+        key_list.append(key)
+        value_list.append(Formattable(value))
+    if not lang:
+        lang = 'en'
+    locale = Locale(lang)
+    return MessageFormat(msg, locale).format(key_list, value_list)

tests/__init__.py

+from . import test_icuformat  # noqa: F401

tests/test_icuformat.py

+###############################################################################
+#
+#    OpenERP, Open Source Management Solution
+#    Copyright (C) 2019 XCG Consulting (http://www.xcg-consulting.fr/)
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU Affero General Public License as
+#    published by the Free Software Foundation, either version 3 of the
+#    License, or (at your option) any later version.
+#
+#    This program 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 Affero General Public License for more details.
+#
+#    You should have received a copy of the GNU Affero General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+###############################################################################
+from odoo import tests
+
+from odoo.addons.icuformat import icuformat
+
+
+class Test(tests.TransactionCase):
+    def test_simple(self):
+        msg = '{test}'
+        d = {'test': 'foobar'}
+        expected = 'foobar'
+        self.assertEqual(expected, icuformat('en', msg, d))
+
+    def test_nothing_to_format(self):
+        msg = 'test'
+        d = dict()
+        self.assertEqual(msg, icuformat('en', msg, d))
+
+    def test_nested_plural_select(self):
+        msg = (
+            "{gender_of_host, select, "
+            "female {"
+            "{num_guests, plural, offset:1 "
+            "=0 {{host} does not give a party.}"
+            "=1 {{host} invites {guest} to her party.}"
+            "=2 {{host} invites {guest} and one other person to her party.}"
+            "other {{host} invites {guest} and # other people to her party.}}}"
+            "male {"
+            "{num_guests, plural, offset:1 "
+            "=0 {{host} does not give a party.}"
+            "=1 {{host} invites {guest} to his party.}"
+            "=2 {{host} invites {guest} and one other person to his party.}"
+            "other {{host} invites {guest} and # other people to his party.}}}"
+            "other {"
+            "{num_guests, plural, offset:1 "
+            "=0 {{host} does not give a party.}"
+            "=1 {{host} invites {guest} to their party.}"
+            "=2 {{host} invites {guest} and one other person to their party.}"
+            "other {{host} invites {guest} and # other people to their party.}"
+            "}}}"
+        )
+        d = dict(
+            gender_of_host='female',
+            num_guests=1005,
+            host='Ms. Marple',
+            guest='Robert')
+        expected = (
+            'Ms. Marple invites Robert and 1,004 other people to her party.'
+        )
+        self.assertEqual(expected, icuformat('en', msg, d))