PICARD-1856: Use gettext.pgettext in Python 3.8

If available, use gettext.pgettext. Fall back to custom implementation for older Python versions.

Author: phw

.pylintrc

@@ -283,7 +283,8 @@ min-similarity-lines=4
 
 # List of additional names supposed to be defined in builtins. Remember that
 # you should avoid defining new builtins when possible.
-additional-builtins=_, N_, ngettext, gettext_countries, gettext_attributes
+additional-builtins=_, N_, ngettext, gettext_countries,
+                    gettext_attributes, pgettext_attributes
 
 # Tells whether unused global variables should be treated as a violation.
 allow-global-unused-variables=yes

picard/coverart/utils.py

@@ -23,7 +23,6 @@
 
 
 from picard.const import MB_ATTRIBUTES
-from picard.i18n import gettext_attr
 
 
 # list of types from http://musicbrainz.org/doc/Cover_Art/Types
@@ -46,4 +45,4 @@ def translate_caa_type(name):
         return _(CAA_TYPES_TR[name])
     else:
         title = CAA_TYPES_TR.get(name, name)
-        return gettext_attr(title, "cover_art_type")
+        return pgettext_attributes("cover_art_type", title)

picard/i18n.py

@@ -98,14 +98,22 @@ def setup_gettext(localedir, ui_language=None, logger=None):
     builtins.__dict__['gettext_countries'] = trans_countries.gettext
     builtins.__dict__['gettext_attributes'] = trans_attributes.gettext
 
+    if hasattr(trans_attributes, 'pgettext'):
+        builtins.__dict__['pgettext_attributes'] = trans_attributes.pgettext
+    else:
+        def pgettext(context, message):
+            return gettext_ctxt(trans_attributes.gettext, message, context)
+        builtins.__dict__['pgettext_attributes'] = pgettext
+
     logger("_ = %r", _)
     logger("N_ = %r", N_)
     logger("ngettext = %r", ngettext)
     logger("gettext_countries = %r", gettext_countries)
     logger("gettext_attributes = %r", gettext_attributes)
+    logger("pgettext_attributes = %r", pgettext_attributes)
 
 
-# Workaround for po files with msgctxt which isn't supported by current python
+# Workaround for po files with msgctxt which isn't supported by Python < 3.8
 # gettext
 # msgctxt are used within attributes.po, and gettext is failing to translate
 # strings due to that
@@ -123,8 +131,3 @@ def gettext_ctxt(gettext_, message, context=None):
         # no translation found, return original message
         return message
     return translated
-
-
-def gettext_attr(message, context=None):
-    """Translate MB attributes, depending on context"""
-    return gettext_ctxt(gettext_attributes, message, context)

picard/ui/options/releases.py

@@ -41,7 +41,6 @@
     RELEASE_SECONDARY_GROUPS,
 )
 from picard.const.sys import IS_WIN
-from picard.i18n import gettext_attr
 
 from picard.ui.options import (
     OptionsPage,
@@ -171,7 +170,7 @@ def __init__(self, parent=None):
         self._release_type_sliders = {}
 
         def add_slider(name, griditer, context):
-            label = gettext_attr(name, context)
+            label = pgettext_attributes(context, name)
             self._release_type_sliders[name] = \
                 ReleaseTypeScore(self.ui.type_group,
                                  self.ui.gridLayout,
@@ -184,7 +183,7 @@ def add_slider(name, griditer, context):
         for name in RELEASE_PRIMARY_GROUPS:
             add_slider(name, griditer, context='release_group_primary_type')
         for name in sorted(RELEASE_SECONDARY_GROUPS,
-                           key=lambda v: gettext_attr(v, 'release_group_secondary_type')):
+                           key=lambda v: pgettext_attributes('release_group_secondary_type', v)):
             add_slider(name, griditer, context='release_group_secondary_type')
 
         self.reset_preferred_types_btn = QtWidgets.QPushButton(self.ui.type_group)
@@ -264,7 +263,7 @@ def _load_list_items(self, setting, source, list1, list2):
             source_list = [(c[0], gettext_countries(c[1])) for c in
                            source.items()]
         elif setting == "preferred_release_formats":
-            source_list = [(c[0], gettext_attr(c[1], "medium_format")) for c
+            source_list = [(c[0], pgettext_attributes("medium_format", c[1])) for c
                            in source.items()]
         else:
             source_list = [(c[0], _(c[1])) for c in source.items()]

setup.cfg

@@ -7,7 +7,7 @@
 # E501: line too long (xx > 79 characters)
 # W503: line break occurred before a binary operator
 ignore = E127,E128,E129,E226,E241,E501,W503
-builtins = _,N_,ngettext,gettext_attributes,gettext_countries,string_
+builtins = _,N_,ngettext,gettext_attributes,pgettext_attributes,gettext_countries,string_
 exclude = ui_*.py,picard/resources.py
 
 [coverage:run]