2dce8c92f6
Using of locals() for formatting string is a nasty thing because: 1) It is not so clear as using explicit dicts 2) It could produce hidden errors during refactoring 3) Changing name of variable causes change in message 4) Creating a lot of unused variables fixes bug 1171936 Change-Id: I293d7ebb875f65cce322d4938d1ae323f3aded8d
1.4 KiB
Internationalization
nova uses gettext so that user-facing strings such as log messages appear in the appropriate language in different locales.
To use gettext, make sure that the strings passed to the logger are
wrapped in a _() function call. For example:
LOG.debug(_("block_device_mapping %s"), block_device_mapping)Do not use locals() for formatting messages because: 1.
It is not as clear as using explicit dicts. 2. It could produce hidden
errors during refactoring. 3. Changing the name of a variable causes a
change in the message. 4. It creates a lot of otherwise unused
variables.
If you do not follow the project conventions, your code may cause the LocalizationTestCase.test_multiple_positional_format_placeholders test to fail in nova/tests/test_localization.py.
The _() function is brought into the global scope by
doing:
from nova.openstack.common import gettextutils
gettextutils.install('nova')These lines are needed in any toplevel script before any nova modules are imported. If this code is missing, it may result in an error that looks like:
NameError: name '_' is not definedThe gettextutils.install() function also queries the NOVA_LOCALEDIR environment variable to allow overriding the default localedir with a specific custom location for Nova's message catalog.