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1 .. -*- mode: rst; encoding: utf-8 -*-
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2
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3 ============
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4 Introduction
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5 ============
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6
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7 The functionality Babel provides for internationalization (I18n) and
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8 localization (L10N) can be separated into two different aspects:
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9
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10 * tools to build and work with ``gettext`` message catalogs, and
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11 * a Python interface to the CLDR (Common Locale Data Repository), providing
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12 access to various locale display names, localized number and date
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13 formatting, etc.
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14
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15 .. contents:: Contents
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16 :depth: 2
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17 .. sectnum::
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18
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19
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20 Message Catalogs
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21 ================
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22
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23 While the Python standard library includes a
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24 `gettext <http://docs.python.org/lib/module-gettext.html>`_ module that enables
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25 applications to use message catalogs, it requires developers to build these
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26 catalogs using GNU tools such as ``xgettext``, ``msgmerge``, and ``msgfmt``.
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27 And while ``xgettext`` does have support for extracting messages from Python
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28 files, it does not know how to deal with other kinds of files commonly found
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29 in Python web-applications, such as templates, nor does it provide an easy
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30 extensibility mechanism to add such support.
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31
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32 Babel addresses this by providing a framework where various extraction methods
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33 can be plugged in to a larger message extraction framework, and also removes
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34 the dependency on the GNU ``gettext`` tools for common tasks, as these aren't
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35 necessarily available on all platforms. See `Working with Message Catalogs`_
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36 for details on this aspect of Babel.
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37
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38 .. _`Working with Message Catalogs`: messages.html
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39
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40
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41 Locale Data
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42 ===========
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43
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44 Furthermore, while the Python standard library does include support for basic
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45 localization with respect to the formatting of numbers and dates (the
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46 `locale <http://docs.python.org/lib/module-locale.html>`_ module, among others),
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47 this support is based on the assumption that there will be only one specific
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48 locale used per process (at least simultaneously.) Also, it doesn't provide
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49 access to other kinds of locale data, such as the localized names of countries,
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50 languages, or time-zones, which are frequently needed in web-based applications.
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51
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52 For these requirements, Babel includes data extracted from the `Common Locale
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53 Data Repository (CLDR) <http://unicode.org/cldr/>`_, and provides a number of
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54 convenient methods for accessing and using this data. See `Locale Display
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55 Names`_, `Date Formatting`_, and `Number Formatting`_ for more information on
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56 this aspect of Babel.
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57
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58
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59 .. _`Locale Display Names`: display.html
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60 .. _`Date Formatting`: dates.html
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61 .. _`Number Formatting`: numbers.html
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