1:mod:`gettext` --- Multilingual internationalization services 2============================================================= 3 4.. module:: gettext 5 :synopsis: Multilingual internationalization services. 6 7.. moduleauthor:: Barry A. Warsaw <barry@python.org> 8.. sectionauthor:: Barry A. Warsaw <barry@python.org> 9 10**Source code:** :source:`Lib/gettext.py` 11 12-------------- 13 14The :mod:`gettext` module provides internationalization (I18N) and localization 15(L10N) services for your Python modules and applications. It supports both the 16GNU :program:`gettext` message catalog API and a higher level, class-based API that may 17be more appropriate for Python files. The interface described below allows you 18to write your module and application messages in one natural language, and 19provide a catalog of translated messages for running under different natural 20languages. 21 22Some hints on localizing your Python modules and applications are also given. 23 24 25GNU :program:`gettext` API 26-------------------------- 27 28The :mod:`gettext` module defines the following API, which is very similar to 29the GNU :program:`gettext` API. If you use this API you will affect the 30translation of your entire application globally. Often this is what you want if 31your application is monolingual, with the choice of language dependent on the 32locale of your user. If you are localizing a Python module, or if your 33application needs to switch languages on the fly, you probably want to use the 34class-based API instead. 35 36 37.. function:: bindtextdomain(domain, localedir=None) 38 39 Bind the *domain* to the locale directory *localedir*. More concretely, 40 :mod:`gettext` will look for binary :file:`.mo` files for the given domain using 41 the path (on Unix): :file:`{localedir}/{language}/LC_MESSAGES/{domain}.mo`, where 42 *language* is searched for in the environment variables :envvar:`LANGUAGE`, 43 :envvar:`LC_ALL`, :envvar:`LC_MESSAGES`, and :envvar:`LANG` respectively. 44 45 If *localedir* is omitted or ``None``, then the current binding for *domain* is 46 returned. [#]_ 47 48 49.. function:: bind_textdomain_codeset(domain, codeset=None) 50 51 Bind the *domain* to *codeset*, changing the encoding of byte strings 52 returned by the :func:`lgettext`, :func:`ldgettext`, :func:`lngettext` 53 and :func:`ldngettext` functions. 54 If *codeset* is omitted, then the current binding is returned. 55 56 .. deprecated-removed:: 3.8 3.10 57 58 59.. function:: textdomain(domain=None) 60 61 Change or query the current global domain. If *domain* is ``None``, then the 62 current global domain is returned, otherwise the global domain is set to 63 *domain*, which is returned. 64 65 66.. index:: single: _ (underscore); gettext 67.. function:: gettext(message) 68 69 Return the localized translation of *message*, based on the current global 70 domain, language, and locale directory. This function is usually aliased as 71 :func:`_` in the local namespace (see examples below). 72 73 74.. function:: dgettext(domain, message) 75 76 Like :func:`.gettext`, but look the message up in the specified *domain*. 77 78 79.. function:: ngettext(singular, plural, n) 80 81 Like :func:`.gettext`, but consider plural forms. If a translation is found, 82 apply the plural formula to *n*, and return the resulting message (some 83 languages have more than two plural forms). If no translation is found, return 84 *singular* if *n* is 1; return *plural* otherwise. 85 86 The Plural formula is taken from the catalog header. It is a C or Python 87 expression that has a free variable *n*; the expression evaluates to the index 88 of the plural in the catalog. See 89 `the GNU gettext documentation <https://www.gnu.org/software/gettext/manual/gettext.html>`__ 90 for the precise syntax to be used in :file:`.po` files and the 91 formulas for a variety of languages. 92 93 94.. function:: dngettext(domain, singular, plural, n) 95 96 Like :func:`ngettext`, but look the message up in the specified *domain*. 97 98 99.. function:: pgettext(context, message) 100.. function:: dpgettext(domain, context, message) 101.. function:: npgettext(context, singular, plural, n) 102.. function:: dnpgettext(domain, context, singular, plural, n) 103 104 Similar to the corresponding functions without the ``p`` in the prefix (that 105 is, :func:`gettext`, :func:`dgettext`, :func:`ngettext`, :func:`dngettext`), 106 but the translation is restricted to the given message *context*. 107 108 .. versionadded:: 3.8 109 110 111.. function:: lgettext(message) 112.. function:: ldgettext(domain, message) 113.. function:: lngettext(singular, plural, n) 114.. function:: ldngettext(domain, singular, plural, n) 115 116 Equivalent to the corresponding functions without the ``l`` prefix 117 (:func:`.gettext`, :func:`dgettext`, :func:`ngettext` and :func:`dngettext`), 118 but the translation is returned as a byte string encoded in the preferred 119 system encoding if no other encoding was explicitly set with 120 :func:`bind_textdomain_codeset`. 121 122 .. warning:: 123 124 These functions should be avoided in Python 3, because they return 125 encoded bytes. It's much better to use alternatives which return 126 Unicode strings instead, since most Python applications will want to 127 manipulate human readable text as strings instead of bytes. Further, 128 it's possible that you may get unexpected Unicode-related exceptions 129 if there are encoding problems with the translated strings. 130 131 .. deprecated-removed:: 3.8 3.10 132 133 134Note that GNU :program:`gettext` also defines a :func:`dcgettext` method, but 135this was deemed not useful and so it is currently unimplemented. 136 137Here's an example of typical usage for this API:: 138 139 import gettext 140 gettext.bindtextdomain('myapplication', '/path/to/my/language/directory') 141 gettext.textdomain('myapplication') 142 _ = gettext.gettext 143 # ... 144 print(_('This is a translatable string.')) 145 146 147Class-based API 148--------------- 149 150The class-based API of the :mod:`gettext` module gives you more flexibility and 151greater convenience than the GNU :program:`gettext` API. It is the recommended 152way of localizing your Python applications and modules. :mod:`!gettext` defines 153a :class:`GNUTranslations` class which implements the parsing of GNU :file:`.mo` format 154files, and has methods for returning strings. Instances of this class can also 155install themselves in the built-in namespace as the function :func:`_`. 156 157 158.. function:: find(domain, localedir=None, languages=None, all=False) 159 160 This function implements the standard :file:`.mo` file search algorithm. It 161 takes a *domain*, identical to what :func:`textdomain` takes. Optional 162 *localedir* is as in :func:`bindtextdomain`. Optional *languages* is a list of 163 strings, where each string is a language code. 164 165 If *localedir* is not given, then the default system locale directory is used. 166 [#]_ If *languages* is not given, then the following environment variables are 167 searched: :envvar:`LANGUAGE`, :envvar:`LC_ALL`, :envvar:`LC_MESSAGES`, and 168 :envvar:`LANG`. The first one returning a non-empty value is used for the 169 *languages* variable. The environment variables should contain a colon separated 170 list of languages, which will be split on the colon to produce the expected list 171 of language code strings. 172 173 :func:`find` then expands and normalizes the languages, and then iterates 174 through them, searching for an existing file built of these components: 175 176 :file:`{localedir}/{language}/LC_MESSAGES/{domain}.mo` 177 178 The first such file name that exists is returned by :func:`find`. If no such 179 file is found, then ``None`` is returned. If *all* is given, it returns a list 180 of all file names, in the order in which they appear in the languages list or 181 the environment variables. 182 183 184.. function:: translation(domain, localedir=None, languages=None, class_=None, fallback=False, codeset=None) 185 186 Return a :class:`*Translations` instance based on the *domain*, *localedir*, 187 and *languages*, which are first passed to :func:`find` to get a list of the 188 associated :file:`.mo` file paths. Instances with identical :file:`.mo` file 189 names are cached. The actual class instantiated is *class_* if 190 provided, otherwise :class:`GNUTranslations`. The class's constructor must 191 take a single :term:`file object` argument. If provided, *codeset* will change 192 the charset used to encode translated strings in the 193 :meth:`~NullTranslations.lgettext` and :meth:`~NullTranslations.lngettext` 194 methods. 195 196 If multiple files are found, later files are used as fallbacks for earlier ones. 197 To allow setting the fallback, :func:`copy.copy` is used to clone each 198 translation object from the cache; the actual instance data is still shared with 199 the cache. 200 201 If no :file:`.mo` file is found, this function raises :exc:`OSError` if 202 *fallback* is false (which is the default), and returns a 203 :class:`NullTranslations` instance if *fallback* is true. 204 205 .. versionchanged:: 3.3 206 :exc:`IOError` used to be raised instead of :exc:`OSError`. 207 208 .. deprecated-removed:: 3.8 3.10 209 The *codeset* parameter. 210 211 212.. function:: install(domain, localedir=None, codeset=None, names=None) 213 214 This installs the function :func:`_` in Python's builtins namespace, based on 215 *domain*, *localedir*, and *codeset* which are passed to the function 216 :func:`translation`. 217 218 For the *names* parameter, please see the description of the translation 219 object's :meth:`~NullTranslations.install` method. 220 221 As seen below, you usually mark the strings in your application that are 222 candidates for translation, by wrapping them in a call to the :func:`_` 223 function, like this:: 224 225 print(_('This string will be translated.')) 226 227 For convenience, you want the :func:`_` function to be installed in Python's 228 builtins namespace, so it is easily accessible in all modules of your 229 application. 230 231 .. deprecated-removed:: 3.8 3.10 232 The *codeset* parameter. 233 234 235The :class:`NullTranslations` class 236^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 237 238Translation classes are what actually implement the translation of original 239source file message strings to translated message strings. The base class used 240by all translation classes is :class:`NullTranslations`; this provides the basic 241interface you can use to write your own specialized translation classes. Here 242are the methods of :class:`!NullTranslations`: 243 244 245.. class:: NullTranslations(fp=None) 246 247 Takes an optional :term:`file object` *fp*, which is ignored by the base class. 248 Initializes "protected" instance variables *_info* and *_charset* which are set 249 by derived classes, as well as *_fallback*, which is set through 250 :meth:`add_fallback`. It then calls ``self._parse(fp)`` if *fp* is not 251 ``None``. 252 253 .. method:: _parse(fp) 254 255 No-op in the base class, this method takes file object *fp*, and reads 256 the data from the file, initializing its message catalog. If you have an 257 unsupported message catalog file format, you should override this method 258 to parse your format. 259 260 261 .. method:: add_fallback(fallback) 262 263 Add *fallback* as the fallback object for the current translation object. 264 A translation object should consult the fallback if it cannot provide a 265 translation for a given message. 266 267 268 .. method:: gettext(message) 269 270 If a fallback has been set, forward :meth:`!gettext` to the fallback. 271 Otherwise, return *message*. Overridden in derived classes. 272 273 274 .. method:: ngettext(singular, plural, n) 275 276 If a fallback has been set, forward :meth:`!ngettext` to the fallback. 277 Otherwise, return *singular* if *n* is 1; return *plural* otherwise. 278 Overridden in derived classes. 279 280 281 .. method:: pgettext(context, message) 282 283 If a fallback has been set, forward :meth:`pgettext` to the fallback. 284 Otherwise, return the translated message. Overridden in derived classes. 285 286 .. versionadded:: 3.8 287 288 289 .. method:: npgettext(context, singular, plural, n) 290 291 If a fallback has been set, forward :meth:`npgettext` to the fallback. 292 Otherwise, return the translated message. Overridden in derived classes. 293 294 .. versionadded:: 3.8 295 296 297 .. method:: lgettext(message) 298 .. method:: lngettext(singular, plural, n) 299 300 Equivalent to :meth:`.gettext` and :meth:`.ngettext`, but the translation 301 is returned as a byte string encoded in the preferred system encoding 302 if no encoding was explicitly set with :meth:`set_output_charset`. 303 Overridden in derived classes. 304 305 .. warning:: 306 307 These methods should be avoided in Python 3. See the warning for the 308 :func:`lgettext` function. 309 310 .. deprecated-removed:: 3.8 3.10 311 312 313 .. method:: info() 314 315 Return the "protected" :attr:`_info` variable, a dictionary containing 316 the metadata found in the message catalog file. 317 318 319 .. method:: charset() 320 321 Return the encoding of the message catalog file. 322 323 324 .. method:: output_charset() 325 326 Return the encoding used to return translated messages in :meth:`.lgettext` 327 and :meth:`.lngettext`. 328 329 .. deprecated-removed:: 3.8 3.10 330 331 332 .. method:: set_output_charset(charset) 333 334 Change the encoding used to return translated messages. 335 336 .. deprecated-removed:: 3.8 3.10 337 338 339 .. method:: install(names=None) 340 341 This method installs :meth:`.gettext` into the built-in namespace, 342 binding it to ``_``. 343 344 If the *names* parameter is given, it must be a sequence containing the 345 names of functions you want to install in the builtins namespace in 346 addition to :func:`_`. Supported names are ``'gettext'``, ``'ngettext'``, 347 ``'pgettext'``, ``'npgettext'``, ``'lgettext'``, and ``'lngettext'``. 348 349 Note that this is only one way, albeit the most convenient way, to make 350 the :func:`_` function available to your application. Because it affects 351 the entire application globally, and specifically the built-in namespace, 352 localized modules should never install :func:`_`. Instead, they should use 353 this code to make :func:`_` available to their module:: 354 355 import gettext 356 t = gettext.translation('mymodule', ...) 357 _ = t.gettext 358 359 This puts :func:`_` only in the module's global namespace and so only 360 affects calls within this module. 361 362 .. versionchanged:: 3.8 363 Added ``'pgettext'`` and ``'npgettext'``. 364 365 366The :class:`GNUTranslations` class 367^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 368 369The :mod:`gettext` module provides one additional class derived from 370:class:`NullTranslations`: :class:`GNUTranslations`. This class overrides 371:meth:`_parse` to enable reading GNU :program:`gettext` format :file:`.mo` files 372in both big-endian and little-endian format. 373 374:class:`GNUTranslations` parses optional metadata out of the translation 375catalog. It is convention with GNU :program:`gettext` to include metadata as 376the translation for the empty string. This metadata is in :rfc:`822`\ -style 377``key: value`` pairs, and should contain the ``Project-Id-Version`` key. If the 378key ``Content-Type`` is found, then the ``charset`` property is used to 379initialize the "protected" :attr:`_charset` instance variable, defaulting to 380``None`` if not found. If the charset encoding is specified, then all message 381ids and message strings read from the catalog are converted to Unicode using 382this encoding, else ASCII is assumed. 383 384Since message ids are read as Unicode strings too, all :meth:`*gettext` methods 385will assume message ids as Unicode strings, not byte strings. 386 387The entire set of key/value pairs are placed into a dictionary and set as the 388"protected" :attr:`_info` instance variable. 389 390If the :file:`.mo` file's magic number is invalid, the major version number is 391unexpected, or if other problems occur while reading the file, instantiating a 392:class:`GNUTranslations` class can raise :exc:`OSError`. 393 394.. class:: GNUTranslations 395 396 The following methods are overridden from the base class implementation: 397 398 .. method:: gettext(message) 399 400 Look up the *message* id in the catalog and return the corresponding message 401 string, as a Unicode string. If there is no entry in the catalog for the 402 *message* id, and a fallback has been set, the look up is forwarded to the 403 fallback's :meth:`~NullTranslations.gettext` method. Otherwise, the 404 *message* id is returned. 405 406 407 .. method:: ngettext(singular, plural, n) 408 409 Do a plural-forms lookup of a message id. *singular* is used as the message id 410 for purposes of lookup in the catalog, while *n* is used to determine which 411 plural form to use. The returned message string is a Unicode string. 412 413 If the message id is not found in the catalog, and a fallback is specified, 414 the request is forwarded to the fallback's :meth:`~NullTranslations.ngettext` 415 method. Otherwise, when *n* is 1 *singular* is returned, and *plural* is 416 returned in all other cases. 417 418 Here is an example:: 419 420 n = len(os.listdir('.')) 421 cat = GNUTranslations(somefile) 422 message = cat.ngettext( 423 'There is %(num)d file in this directory', 424 'There are %(num)d files in this directory', 425 n) % {'num': n} 426 427 428 .. method:: pgettext(context, message) 429 430 Look up the *context* and *message* id in the catalog and return the 431 corresponding message string, as a Unicode string. If there is no 432 entry in the catalog for the *message* id and *context*, and a fallback 433 has been set, the look up is forwarded to the fallback's 434 :meth:`pgettext` method. Otherwise, the *message* id is returned. 435 436 .. versionadded:: 3.8 437 438 439 .. method:: npgettext(context, singular, plural, n) 440 441 Do a plural-forms lookup of a message id. *singular* is used as the 442 message id for purposes of lookup in the catalog, while *n* is used to 443 determine which plural form to use. 444 445 If the message id for *context* is not found in the catalog, and a 446 fallback is specified, the request is forwarded to the fallback's 447 :meth:`npgettext` method. Otherwise, when *n* is 1 *singular* is 448 returned, and *plural* is returned in all other cases. 449 450 .. versionadded:: 3.8 451 452 453 .. method:: lgettext(message) 454 .. method:: lngettext(singular, plural, n) 455 456 Equivalent to :meth:`.gettext` and :meth:`.ngettext`, but the translation 457 is returned as a byte string encoded in the preferred system encoding 458 if no encoding was explicitly set with 459 :meth:`~NullTranslations.set_output_charset`. 460 461 .. warning:: 462 463 These methods should be avoided in Python 3. See the warning for the 464 :func:`lgettext` function. 465 466 .. deprecated-removed:: 3.8 3.10 467 468 469Solaris message catalog support 470^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 471 472The Solaris operating system defines its own binary :file:`.mo` file format, but 473since no documentation can be found on this format, it is not supported at this 474time. 475 476 477The Catalog constructor 478^^^^^^^^^^^^^^^^^^^^^^^ 479 480.. index:: single: GNOME 481 482GNOME uses a version of the :mod:`gettext` module by James Henstridge, but this 483version has a slightly different API. Its documented usage was:: 484 485 import gettext 486 cat = gettext.Catalog(domain, localedir) 487 _ = cat.gettext 488 print(_('hello world')) 489 490For compatibility with this older module, the function :func:`Catalog` is an 491alias for the :func:`translation` function described above. 492 493One difference between this module and Henstridge's: his catalog objects 494supported access through a mapping API, but this appears to be unused and so is 495not currently supported. 496 497 498Internationalizing your programs and modules 499-------------------------------------------- 500 501Internationalization (I18N) refers to the operation by which a program is made 502aware of multiple languages. Localization (L10N) refers to the adaptation of 503your program, once internationalized, to the local language and cultural habits. 504In order to provide multilingual messages for your Python programs, you need to 505take the following steps: 506 507#. prepare your program or module by specially marking translatable strings 508 509#. run a suite of tools over your marked files to generate raw messages catalogs 510 511#. create language-specific translations of the message catalogs 512 513#. use the :mod:`gettext` module so that message strings are properly translated 514 515In order to prepare your code for I18N, you need to look at all the strings in 516your files. Any string that needs to be translated should be marked by wrapping 517it in ``_('...')`` --- that is, a call to the function :func:`_`. For example:: 518 519 filename = 'mylog.txt' 520 message = _('writing a log message') 521 with open(filename, 'w') as fp: 522 fp.write(message) 523 524In this example, the string ``'writing a log message'`` is marked as a candidate 525for translation, while the strings ``'mylog.txt'`` and ``'w'`` are not. 526 527There are a few tools to extract the strings meant for translation. 528The original GNU :program:`gettext` only supported C or C++ source 529code but its extended version :program:`xgettext` scans code written 530in a number of languages, including Python, to find strings marked as 531translatable. `Babel <http://babel.pocoo.org/>`__ is a Python 532internationalization library that includes a :file:`pybabel` script to 533extract and compile message catalogs. François Pinard's program 534called :program:`xpot` does a similar job and is available as part of 535his `po-utils package <https://github.com/pinard/po-utils>`__. 536 537(Python also includes pure-Python versions of these programs, called 538:program:`pygettext.py` and :program:`msgfmt.py`; some Python distributions 539will install them for you. :program:`pygettext.py` is similar to 540:program:`xgettext`, but only understands Python source code and 541cannot handle other programming languages such as C or C++. 542:program:`pygettext.py` supports a command-line interface similar to 543:program:`xgettext`; for details on its use, run ``pygettext.py 544--help``. :program:`msgfmt.py` is binary compatible with GNU 545:program:`msgfmt`. With these two programs, you may not need the GNU 546:program:`gettext` package to internationalize your Python 547applications.) 548 549:program:`xgettext`, :program:`pygettext`, and similar tools generate 550:file:`.po` files that are message catalogs. They are structured 551human-readable files that contain every marked string in the source 552code, along with a placeholder for the translated versions of these 553strings. 554 555Copies of these :file:`.po` files are then handed over to the 556individual human translators who write translations for every 557supported natural language. They send back the completed 558language-specific versions as a :file:`<language-name>.po` file that's 559compiled into a machine-readable :file:`.mo` binary catalog file using 560the :program:`msgfmt` program. The :file:`.mo` files are used by the 561:mod:`gettext` module for the actual translation processing at 562run-time. 563 564How you use the :mod:`gettext` module in your code depends on whether you are 565internationalizing a single module or your entire application. The next two 566sections will discuss each case. 567 568 569Localizing your module 570^^^^^^^^^^^^^^^^^^^^^^ 571 572If you are localizing your module, you must take care not to make global 573changes, e.g. to the built-in namespace. You should not use the GNU :program:`gettext` 574API but instead the class-based API. 575 576Let's say your module is called "spam" and the module's various natural language 577translation :file:`.mo` files reside in :file:`/usr/share/locale` in GNU 578:program:`gettext` format. Here's what you would put at the top of your 579module:: 580 581 import gettext 582 t = gettext.translation('spam', '/usr/share/locale') 583 _ = t.gettext 584 585 586Localizing your application 587^^^^^^^^^^^^^^^^^^^^^^^^^^^ 588 589If you are localizing your application, you can install the :func:`_` function 590globally into the built-in namespace, usually in the main driver file of your 591application. This will let all your application-specific files just use 592``_('...')`` without having to explicitly install it in each file. 593 594In the simple case then, you need only add the following bit of code to the main 595driver file of your application:: 596 597 import gettext 598 gettext.install('myapplication') 599 600If you need to set the locale directory, you can pass it into the 601:func:`install` function:: 602 603 import gettext 604 gettext.install('myapplication', '/usr/share/locale') 605 606 607Changing languages on the fly 608^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 609 610If your program needs to support many languages at the same time, you may want 611to create multiple translation instances and then switch between them 612explicitly, like so:: 613 614 import gettext 615 616 lang1 = gettext.translation('myapplication', languages=['en']) 617 lang2 = gettext.translation('myapplication', languages=['fr']) 618 lang3 = gettext.translation('myapplication', languages=['de']) 619 620 # start by using language1 621 lang1.install() 622 623 # ... time goes by, user selects language 2 624 lang2.install() 625 626 # ... more time goes by, user selects language 3 627 lang3.install() 628 629 630Deferred translations 631^^^^^^^^^^^^^^^^^^^^^ 632 633In most coding situations, strings are translated where they are coded. 634Occasionally however, you need to mark strings for translation, but defer actual 635translation until later. A classic example is:: 636 637 animals = ['mollusk', 638 'albatross', 639 'rat', 640 'penguin', 641 'python', ] 642 # ... 643 for a in animals: 644 print(a) 645 646Here, you want to mark the strings in the ``animals`` list as being 647translatable, but you don't actually want to translate them until they are 648printed. 649 650Here is one way you can handle this situation:: 651 652 def _(message): return message 653 654 animals = [_('mollusk'), 655 _('albatross'), 656 _('rat'), 657 _('penguin'), 658 _('python'), ] 659 660 del _ 661 662 # ... 663 for a in animals: 664 print(_(a)) 665 666This works because the dummy definition of :func:`_` simply returns the string 667unchanged. And this dummy definition will temporarily override any definition 668of :func:`_` in the built-in namespace (until the :keyword:`del` command). Take 669care, though if you have a previous definition of :func:`_` in the local 670namespace. 671 672Note that the second use of :func:`_` will not identify "a" as being 673translatable to the :program:`gettext` program, because the parameter 674is not a string literal. 675 676Another way to handle this is with the following example:: 677 678 def N_(message): return message 679 680 animals = [N_('mollusk'), 681 N_('albatross'), 682 N_('rat'), 683 N_('penguin'), 684 N_('python'), ] 685 686 # ... 687 for a in animals: 688 print(_(a)) 689 690In this case, you are marking translatable strings with the function 691:func:`N_`, which won't conflict with any definition of :func:`_`. 692However, you will need to teach your message extraction program to 693look for translatable strings marked with :func:`N_`. :program:`xgettext`, 694:program:`pygettext`, ``pybabel extract``, and :program:`xpot` all 695support this through the use of the :option:`!-k` command-line switch. 696The choice of :func:`N_` here is totally arbitrary; it could have just 697as easily been :func:`MarkThisStringForTranslation`. 698 699 700Acknowledgements 701---------------- 702 703The following people contributed code, feedback, design suggestions, previous 704implementations, and valuable experience to the creation of this module: 705 706* Peter Funk 707 708* James Henstridge 709 710* Juan David Ibáñez Palomar 711 712* Marc-André Lemburg 713 714* Martin von Löwis 715 716* François Pinard 717 718* Barry Warsaw 719 720* Gustavo Niemeyer 721 722.. rubric:: Footnotes 723 724.. [#] The default locale directory is system dependent; for example, on RedHat Linux 725 it is :file:`/usr/share/locale`, but on Solaris it is :file:`/usr/lib/locale`. 726 The :mod:`gettext` module does not try to support these system dependent 727 defaults; instead its default is :file:`{sys.base_prefix}/share/locale` (see 728 :data:`sys.base_prefix`). For this reason, it is always best to call 729 :func:`bindtextdomain` with an explicit absolute path at the start of your 730 application. 731 732.. [#] See the footnote for :func:`bindtextdomain` above. 733