:mod:`webbrowser` --- Convenient Web-browser controller

=======================================================

.. module:: webbrowser

   :synopsis: Easy-to-use controller for Web browsers.

.. moduleauthor:: Fred L. Drake, Jr. <fdrake@acm.org>

.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>

The :mod:`webbrowser` module provides a high-level interface to allow displaying

Web-based documents to users. Under most circumstances, simply calling the

:func:`open` function from this module will do the right thing.

Under Unix, graphical browsers are preferred under X11, but text-mode browsers

will be used if graphical browsers are not available or an X11 display isn't

available.  If text-mode browsers are used, the calling process will block until

the user exits the browser.

If the environment variable :envvar:`BROWSER` exists, it is interpreted to

override the platform default list of browsers, as a os.pathsep-separated list

of browsers to try in order.  When the value of a list part contains the string

``%s``, then it is  interpreted as a literal browser command line to be used

with the argument URL substituted for ``%s``; if the part does not contain

``%s``, it is simply interpreted as the name of the browser to launch.

For non-Unix platforms, or when a remote browser is available on Unix, the

controlling process will not wait for the user to finish with the browser, but

allow the remote browser to maintain its own windows on the display.  If remote

browsers are not available on Unix, the controlling process will launch a new

browser and wait.

The script :program:`webbrowser` can be used as a command-line interface for the

module. It accepts an URL as the argument. It accepts the following optional

parameters: :option:`-n` opens the URL in a new browser window, if possible;

:option:`-t` opens the URL in a new browser page ("tab"). The options are,

naturally, mutually exclusive.

The following exception is defined:

.. exception:: Error

   Exception raised when a browser control error occurs.

The following functions are defined:

.. function:: open(url[, new=0[, autoraise=1]])

   Display *url* using the default browser. If *new* is 0, the *url* is opened in

   the same browser window if possible.  If *new* is 1, a new browser window is

   opened if possible.  If *new* is 2, a new browser page ("tab") is opened if

   possible.  If *autoraise* is true, the window is raised if possible (note that

   under many window managers this will occur regardless of the setting of this

   variable).

   .. versionchanged:: 2.5

      *new* can now be 2.

.. function:: open_new(url)

   Open *url* in a new window of the default browser, if possible, otherwise, open

   *url* in the only browser window.

.. function:: open_new_tab(url)

   Open *url* in a new page ("tab") of the default browser, if possible, otherwise

   equivalent to :func:`open_new`.

   .. versionadded:: 2.5

.. function:: get([name])

   Return a controller object for the browser type *name*.  If *name* is empty,

   return a controller for a default browser appropriate to the caller's

   environment.

.. function:: register(name, constructor[, instance])

   Register the browser type *name*.  Once a browser type is registered, the

   :func:`get` function can return a controller for that browser type.  If

   *instance* is not provided, or is ``None``, *constructor* will be called without

   parameters to create an instance when needed.  If *instance* is provided,

   *constructor* will never be called, and may be ``None``.

   This entry point is only useful if you plan to either set the :envvar:`BROWSER`

   variable or call :func:`get` with a nonempty argument matching the name of a

   handler you declare.

A number of browser types are predefined.  This table gives the type names that

may be passed to the :func:`get` function and the corresponding instantiations

for the controller classes, all defined in this module.

+-----------------------+-----------------------------------------+-------+

| Type Name             | Class Name                              | Notes |

+=======================+=========================================+=======+

| ``'mozilla'``         | :class:`Mozilla('mozilla')`             |       |

+-----------------------+-----------------------------------------+-------+

| ``'firefox'``         | :class:`Mozilla('mozilla')`             |       |

+-----------------------+-----------------------------------------+-------+

| ``'netscape'``        | :class:`Mozilla('netscape')`            |       |

+-----------------------+-----------------------------------------+-------+

| ``'galeon'``          | :class:`Galeon('galeon')`               |       |

+-----------------------+-----------------------------------------+-------+

| ``'epiphany'``        | :class:`Galeon('epiphany')`             |       |

+-----------------------+-----------------------------------------+-------+

| ``'skipstone'``       | :class:`BackgroundBrowser('skipstone')` |       |

+-----------------------+-----------------------------------------+-------+

| ``'kfmclient'``       | :class:`Konqueror()`                    | \(1)  |

+-----------------------+-----------------------------------------+-------+

| ``'konqueror'``       | :class:`Konqueror()`                    | \(1)  |

+-----------------------+-----------------------------------------+-------+

| ``'kfm'``             | :class:`Konqueror()`                    | \(1)  |

+-----------------------+-----------------------------------------+-------+

| ``'mosaic'``          | :class:`BackgroundBrowser('mosaic')`    |       |

+-----------------------+-----------------------------------------+-------+

| ``'opera'``           | :class:`Opera()`                        |       |

+-----------------------+-----------------------------------------+-------+

| ``'grail'``           | :class:`Grail()`                        |       |

+-----------------------+-----------------------------------------+-------+

| ``'links'``           | :class:`GenericBrowser('links')`        |       |

+-----------------------+-----------------------------------------+-------+

| ``'elinks'``          | :class:`Elinks('elinks')`               |       |

+-----------------------+-----------------------------------------+-------+

| ``'lynx'``            | :class:`GenericBrowser('lynx')`         |       |

+-----------------------+-----------------------------------------+-------+

| ``'w3m'``             | :class:`GenericBrowser('w3m')`          |       |

+-----------------------+-----------------------------------------+-------+

| ``'windows-default'`` | :class:`WindowsDefault`                 | \(2)  |

+-----------------------+-----------------------------------------+-------+

| ``'internet-config'`` | :class:`InternetConfig`                 | \(3)  |

+-----------------------+-----------------------------------------+-------+

| ``'macosx'``          | :class:`MacOSX('default')`              | \(4)  |

+-----------------------+-----------------------------------------+-------+

Notes:

(1)

   "Konqueror" is the file manager for the KDE desktop environment for Unix, and

   only makes sense to use if KDE is running.  Some way of reliably detecting KDE

   would be nice; the :envvar:`KDEDIR` variable is not sufficient.  Note also that

   the name "kfm" is used even when using the :program:`konqueror` command with KDE

   2 --- the implementation selects the best strategy for running Konqueror.

(2)

   Only on Windows platforms.

(3)

   Only on Mac OS platforms; requires the standard MacPython :mod:`ic` module.

(4)

   Only on Mac OS X platform.

Here are some simple examples::

   url = 'http://www.python.org'

   # Open URL in a new tab, if a browser window is already open. 

   webbrowser.open_new_tab(url + '/doc')

   # Open URL in new window, raising the window if possible.

   webbrowser.open_new(url)

.. _browser-controllers:

Browser Controller Objects

--------------------------

Browser controllers provide two methods which parallel two of the module-level

convenience functions:

.. method:: controller.open(url[, new[, autoraise=1]])

   Display *url* using the browser handled by this controller. If *new* is 1, a new

   browser window is opened if possible. If *new* is 2, a new browser page ("tab")

   is opened if possible.

.. method:: controller.open_new(url)

   Open *url* in a new window of the browser handled by this controller, if

   possible, otherwise, open *url* in the only browser window.  Alias

   :func:`open_new`.

.. method:: controller.open_new_tab(url)

   Open *url* in a new page ("tab") of the browser handled by this controller, if

   possible, otherwise equivalent to :func:`open_new`.

   .. versionadded:: 2.5