This change implements the following gettext features, as
discussed recently in python-dev:
In _locale module:
- bind_textdomain_codeset() binding
In gettext module:
- bind_textdomain_codeset() function
- lgettext(), lngettext(), ldgettext(), ldngettext(),
which return translated strings encoded in
preferred system encoding, if
bind_textdomain_codeset() was not used.
- Added equivalent functionality in translate()
function and catalog classes.
Every change was also documented.
diff --git a/Doc/lib/libgettext.tex b/Doc/lib/libgettext.tex
index f2c20f8..57d09d0 100644
--- a/Doc/lib/libgettext.tex
+++ b/Doc/lib/libgettext.tex
@@ -51,6 +51,14 @@
the start of your application.}
\end{funcdesc}
+\begin{funcdesc}{bind_textdomain_codeset}{domain\optional{, codeset}}
+Bind the \var{domain} to \var{codeset}, changing the encoding of
+strings returned by the \function{gettext()} family of functions.
+If \var{codeset} is omitted, then the current binding is returned.
+
+\versionadded{2.4}
+\end{funcdesc}
+
\begin{funcdesc}{textdomain}{\optional{domain}}
Change or query the current global domain. If \var{domain} is
\code{None}, then the current global domain is returned, otherwise the
@@ -64,11 +72,27 @@
examples below).
\end{funcdesc}
+\begin{funcdesc}{lgettext}{message}
+Equivalent to \function{gettext()}, but the translation is returned
+in the preferred system encoding, if no other encoding was explicitly
+set with \function{bind_textdomain_codeset()}.
+
+\versionadded{2.4}
+\end{funcdesc}
+
\begin{funcdesc}{dgettext}{domain, message}
Like \function{gettext()}, but look the message up in the specified
\var{domain}.
\end{funcdesc}
+\begin{funcdesc}{ldgettext}{domain, message}
+Equivalent to \function{dgettext()}, but the translation is returned
+in the preferred system encoding, if no other encoding was explicitly
+set with \function{bind_textdomain_codeset()}.
+
+\versionadded{2.4}
+\end{funcdesc}
+
\begin{funcdesc}{ngettext}{singular, plural, n}
Like \function{gettext()}, but consider plural forms. If a translation
@@ -87,6 +111,14 @@
\end{funcdesc}
+\begin{funcdesc}{lngettext}{singular, plural, n}
+Equivalent to \function{ngettext()}, but the translation is returned
+in the preferred system encoding, if no other encoding was explicitly
+set with \function{bind_textdomain_codeset()}.
+
+\versionadded{2.4}
+\end{funcdesc}
+
\begin{funcdesc}{dngettext}{domain, singular, plural, n}
Like \function{ngettext()}, but look the message up in the specified
\var{domain}.
@@ -94,6 +126,15 @@
\versionadded{2.3}
\end{funcdesc}
+\begin{funcdesc}{ldngettext}{domain, singular, plural, n}
+Equivalent to \function{dngettext()}, but the translation is returned
+in the preferred system encoding, if no other encoding was explicitly
+set with \function{bind_textdomain_codeset()}.
+
+\versionadded{2.4}
+\end{funcdesc}
+
+
Note that GNU \program{gettext} also defines a \function{dcgettext()}
method, but this was deemed not useful and so it is currently
@@ -152,8 +193,8 @@
\end{funcdesc}
\begin{funcdesc}{translation}{domain\optional{, localedir\optional{,
- languages\optional{,
- class_,\optional{fallback}}}}}
+ languages\optional{, class_\optional{,
+ fallback\optional{, codeset}}}}}}
Return a \class{Translations} instance based on the \var{domain},
\var{localedir}, and \var{languages}, which are first passed to
\function{find()} to get a list of the
@@ -161,7 +202,8 @@
identical \file{.mo} file names are cached. The actual class instantiated
is either \var{class_} if provided, otherwise
\class{GNUTranslations}. The class's constructor must take a single
-file object argument.
+file object argument. If provided, \var{codeset} will change the
+charset used to encode translated strings.
If multiple files are found, later files are used as fallbacks for
earlier ones. To allow setting the fallback, \function{copy.copy}
@@ -172,13 +214,17 @@
\exception{IOError} if \var{fallback} is false (which is the default),
and returns a \class{NullTranslations} instance if \var{fallback} is
true.
+
+\versionchanged[Added the \var{codeset} parameter]{2.4}
\end{funcdesc}
-\begin{funcdesc}{install}{domain\optional{, localedir\optional{, unicode}}}
+\begin{funcdesc}{install}{domain\optional{, localedir\optional{, unicode
+ \optional{, codeset}}}}
This installs the function \function{_} in Python's builtin namespace,
-based on \var{domain}, and \var{localedir} which are passed to the
-function \function{translation()}. The \var{unicode} flag is passed to
-the resulting translation object's \method{install} method.
+based on \var{domain}, \var{localedir}, and \var{codeset} which are
+passed to the function \function{translation()}. The \var{unicode}
+flag is passed to the resulting translation object's \method{install}
+method.
As seen below, you usually mark the strings in your application that are
candidates for translation, by wrapping them in a call to the
@@ -191,6 +237,8 @@
For convenience, you want the \function{_()} function to be installed in
Python's builtin namespace, so it is easily accessible in all modules
of your application.
+
+\versionchanged[Added the \var{codeset} parameter]{2.4}
\end{funcdesc}
\subsubsection{The \class{NullTranslations} class}
@@ -223,25 +271,39 @@
\end{methoddesc}
\begin{methoddesc}[NullTranslations]{gettext}{message}
-If a fallback has been set, forward \method{gettext} to the fallback.
+If a fallback has been set, forward \method{gettext()} to the fallback.
Otherwise, return the translated message. Overridden in derived classes.
\end{methoddesc}
+\begin{methoddesc}[NullTranslations]{lgettext}{message}
+If a fallback has been set, forward \method{lgettext()} to the fallback.
+Otherwise, return the translated message. Overridden in derived classes.
+
+\versionadded{2.4}
+\end{methoddesc}
+
\begin{methoddesc}[NullTranslations]{ugettext}{message}
-If a fallback has been set, forward \method{ugettext} to the fallback.
+If a fallback has been set, forward \method{ugettext()} to the fallback.
Otherwise, return the translated message as a Unicode string.
Overridden in derived classes.
\end{methoddesc}
\begin{methoddesc}[NullTranslations]{ngettext}{singular, plural, n}
-If a fallback has been set, forward \method{ngettext} to the fallback.
+If a fallback has been set, forward \method{ngettext()} to the fallback.
Otherwise, return the translated message. Overridden in derived classes.
\versionadded{2.3}
\end{methoddesc}
+\begin{methoddesc}[NullTranslations]{lngettext}{singular, plural, n}
+If a fallback has been set, forward \method{ngettext()} to the fallback.
+Otherwise, return the translated message. Overridden in derived classes.
+
+\versionadded{2.4}
+\end{methoddesc}
+
\begin{methoddesc}[NullTranslations]{ungettext}{singular, plural, n}
-If a fallback has been set, forward \method{ungettext} to the fallback.
+If a fallback has been set, forward \method{ungettext()} to the fallback.
Otherwise, return the translated message as a Unicode string.
Overridden in derived classes.
@@ -256,6 +318,20 @@
Return the ``protected'' \member{_charset} variable.
\end{methoddesc}
+\begin{methoddesc}[NullTranslations]{output_charset}{}
+Return the ``protected'' \member{_output_charset} variable, which
+defines the encoding used to return translated messages.
+
+\versionadded{2.4}
+\end{methoddesc}
+
+\begin{methoddesc}[NullTranslations]{set_output_charset}{charset}
+Change the ``protected'' \member{_output_charset} variable, which
+defines the encoding used to return translated messages.
+
+\versionadded{2.4}
+\end{methoddesc}
+
\begin{methoddesc}[NullTranslations]{install}{\optional{unicode}}
If the \var{unicode} flag is false, this method installs
\method{self.gettext()} into the built-in namespace, binding it to
@@ -323,6 +399,14 @@
Otherwise, the \var{message} id is returned.
\end{methoddesc}
+\begin{methoddesc}[GNUTranslations]{lgettext}{message}
+Equivalent to \method{gettext()}, but the translation is returned
+in the preferred system encoding, if no other encoding was explicitly
+set with \method{set_output_charset()}.
+
+\versionadded{2.4}
+\end{methoddesc}
+
\begin{methoddesc}[GNUTranslations]{ugettext}{message}
Look up the \var{message} id in the catalog and return the
corresponding message string, as a Unicode string. If there is no
@@ -346,6 +430,14 @@
\versionadded{2.3}
\end{methoddesc}
+\begin{methoddesc}[GNUTranslations]{lngettext}{singular, plural, n}
+Equivalent to \method{gettext()}, but the translation is returned
+in the preferred system encoding, if no other encoding was explicitly
+set with \method{set_output_charset()}.
+
+\versionadded{2.4}
+\end{methoddesc}
+
\begin{methoddesc}[GNUTranslations]{ungettext}{singular, plural, n}
Do a plural-forms lookup of a message id. \var{singular} is used as
the message id for purposes of lookup in the catalog, while \var{n} is
@@ -495,7 +587,7 @@
\begin{verbatim}
import gettext
t = gettext.translation('spam', '/usr/share/locale')
-_ = t.gettext
+_ = t.lgettext
\end{verbatim}
If your translators were providing you with Unicode strings in their
@@ -633,6 +725,21 @@
\program{pygettext} and \program{xpot} both support this through the
use of command line switches.
+\subsubsection{\function{gettext()} vs. \function{lgettext()}}
+In Python 2.4 the \function{lgettext()} family of functions were
+introduced. The intention of these functions is to provide an
+alternative which is more compliant with the current
+implementation of GNU gettext. Unlike \function{gettext()}, which
+returns strings encoded with the same codeset used in the
+translation file, \function{lgettext()} will return strings
+encoded with the preferred system encoding, as returned by
+\function{locale.getpreferredencoding()}. Also notice that
+Python 2.4 introduces new functions to explicitly choose
+the codeset used in translated strings. If a codeset is explicitly
+set, even \function{lgettext()} will return translated strings in
+the requested codeset, as would be expected in the GNU gettext
+implementation.
+
\subsection{Acknowledgements}
The following people contributed code, feedback, design suggestions,
@@ -647,4 +754,5 @@
\item Martin von L\"owis
\item Fran\c cois Pinard
\item Barry Warsaw
+ \item Gustavo Niemeyer
\end{itemize}