Trivial refactors for gettextutils

* Favor one-line conditional assignments instead of more verbose
  assignments inside if...else clauses

* Favor the usage of generators instead of explicit for loops for
  perfomance

Change-Id: Idfbbec7cd2efa1ebbf5111abb24cb147edb176ee

4 files changed, 23 insertions, 33 deletions

diff --git a/oslo/i18n/_factory.py b/oslo/i18n/_factory.py
index acd0367..df00aaa 100644
--- a/oslo/i18n/_factory.py
+++ b/oslo/i18n/_factory.py
@@ -41,9 +41,8 @@ class TranslatorFactory(object):
         """
         self.domain = domain
         if localedir is None:
-            localedir = os.environ.get(_locale.get_locale_dir_variable_name(
-                domain
-            ))
+            variable_name = _locale.get_locale_dir_variable_name(domain)
+            localedir = os.environ.get(variable_name)
         self.localedir = localedir
 
     def _make_translation_func(self, domain=None):
@@ -64,11 +63,9 @@ class TranslatorFactory(object):
         """
         if domain is None:
             domain = self.domain
-        t = gettext.translation(
-            domain,
-            localedir=self.localedir,
-            fallback=True,
-        )
+        t = gettext.translation(domain,
+                                localedir=self.localedir,
+                                fallback=True)
         # Use the appropriate method of the translation object based
         # on the python version.
         m = t.gettext if six.PY3 else t.ugettext
diff --git a/oslo/i18n/_message.py b/oslo/i18n/_message.py
index 73cb7bf..93374a4 100644
--- a/oslo/i18n/_message.py
+++ b/oslo/i18n/_message.py
@@ -89,20 +89,14 @@ class Message(six.text_type):
         if not desired_locale:
             system_locale = locale.getdefaultlocale()
             # If the system locale is not available to the runtime use English
-            if not system_locale[0]:
-                desired_locale = 'en_US'
-            else:
-                desired_locale = system_locale[0]
+            desired_locale = system_locale[0] or 'en_US'
 
         locale_dir = os.environ.get(domain.upper() + '_LOCALEDIR')
         lang = gettext.translation(domain,
                                    localedir=locale_dir,
                                    languages=[desired_locale],
                                    fallback=True)
-        if six.PY3:
-            translator = lang.gettext
-        else:
-            translator = lang.ugettext
+        translator = lang.gettext if six.PY3 else lang.ugettext
 
         translated_message = translator(msgid)
         return translated_message
@@ -135,10 +129,10 @@ class Message(six.text_type):
             # Copy each item in case one does not support deep copy.
             params = {}
             if isinstance(self.params, dict):
-                for key, val in self.params.items():
-                    params[key] = self._copy_param(val)
-            for key, val in other.items():
-                params[key] = self._copy_param(val)
+                params.update((key, self._copy_param(val))
+                              for key, val in self.params.items())
+            params.update((key, self._copy_param(val))
+                          for key, val in other.items())
         else:
             params = self._copy_param(other)
         return params
diff --git a/oslo/i18n/_translate.py b/oslo/i18n/_translate.py
index bd81b85..037651a 100644
--- a/oslo/i18n/_translate.py
+++ b/oslo/i18n/_translate.py
@@ -63,9 +63,7 @@ def translate_args(args, desired_locale=None):
     if isinstance(args, tuple):
         return tuple(translate(v, desired_locale) for v in args)
     if isinstance(args, dict):
-        translated_dict = {}
-        for (k, v) in six.iteritems(args):
-            translated_v = translate(v, desired_locale)
-            translated_dict[k] = translated_v
+        translated_dict = dict((key, translate(value, desired_locale))
+                               for key, value in six.iteritems(args))
         return translated_dict
     return translate(args, desired_locale)
diff --git a/oslo/i18n/gettextutils.py b/oslo/i18n/gettextutils.py
index a7285f5..38f78eb 100644
--- a/oslo/i18n/gettextutils.py
+++ b/oslo/i18n/gettextutils.py
@@ -61,13 +61,14 @@ def get_available_languages(domain):
 
     :param domain: the domain to get languages for
     """
+    def find(language, domain, localedir):
+        return gettext.find(domain, localedir=os.environ.get(localedir),
+                            languages=[language])
+
     if domain in _AVAILABLE_LANGUAGES:
         return copy.copy(_AVAILABLE_LANGUAGES[domain])
 
     localedir = '%s_LOCALEDIR' % domain.upper()
-    find = lambda x: gettext.find(domain,
-                                  localedir=os.environ.get(localedir),
-                                  languages=[x])
 
     # NOTE(mrodden): en_US should always be available (and first in case
     # order matters) since our in-line message strings are en_US
@@ -80,9 +81,8 @@ def get_available_languages(domain):
                         getattr(localedata, 'locale_identifiers'))
     locale_identifiers = list_identifiers()
 
-    for i in locale_identifiers:
-        if find(i) is not None:
-            language_list.append(i)
+    language_list.extend(language for language in locale_identifiers
+                         if find(language, domain, localedir))
 
     # NOTE(luisg): Babel>=1.0,<1.3 has a bug where some OpenStack supported
     # locales (e.g. 'zh_CN', and 'zh_TW') aren't supported even though they
@@ -96,9 +96,10 @@ def get_available_languages(domain):
                'zh_Hant_HK': 'zh_HK',
                'zh_Hant': 'zh_TW',
                'fil': 'tl_PH'}
-    for (locale, alias) in six.iteritems(aliases):
-        if locale in language_list and alias not in language_list:
-            language_list.append(alias)
+
+    language_list.extend(alias for locale, alias in six.iteritems(aliases)
+                         if (locale in language_list and
+                             alias not in language_list))
 
     _AVAILABLE_LANGUAGES[domain] = language_list
     return copy.copy(language_list)