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