symbian-qemu-0.9.1-12/python-2.6.1/Doc/library/gdbm.rst
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+:mod:`gdbm` --- GNU's reinterpretation of dbm
+=============================================
+
+.. module:: gdbm
+   :platform: Unix
+   :synopsis: GNU's reinterpretation of dbm.
+
+.. note::
+   The :mod:`gdbm` module has been renamed to :mod:`dbm.gnu` in Python 3.0.  The
+   :term:`2to3` tool will automatically adapt imports when converting your
+   sources to 3.0.
+
+
+.. index:: module: dbm
+
+This module is quite similar to the :mod:`dbm` module, but uses ``gdbm`` instead
+to provide some additional functionality.  Please note that the file formats
+created by ``gdbm`` and ``dbm`` are incompatible.
+
+The :mod:`gdbm` module provides an interface to the GNU DBM library.  ``gdbm``
+objects behave like mappings (dictionaries), except that keys and values are
+always strings. Printing a ``gdbm`` object doesn't print the keys and values,
+and the :meth:`items` and :meth:`values` methods are not supported.
+
+The module defines the following constant and functions:
+
+
+.. exception:: error
+
+   Raised on ``gdbm``\ -specific errors, such as I/O errors. :exc:`KeyError` is
+   raised for general mapping errors like specifying an incorrect key.
+
+
+.. function:: open(filename, [flag, [mode]])
+
+   Open a ``gdbm`` database and return a ``gdbm`` object.  The *filename* argument
+   is the name of the database file.
+
+   The optional *flag* argument can be:
+
+   +---------+-------------------------------------------+
+   | Value   | Meaning                                   |
+   +=========+===========================================+
+   | ``'r'`` | Open existing database for reading only   |
+   |         | (default)                                 |
+   +---------+-------------------------------------------+
+   | ``'w'`` | Open existing database for reading and    |
+   |         | writing                                   |
+   +---------+-------------------------------------------+
+   | ``'c'`` | Open database for reading and writing,    |
+   |         | creating it if it doesn't exist           |
+   +---------+-------------------------------------------+
+   | ``'n'`` | Always create a new, empty database, open |
+   |         | for reading and writing                   |
+   +---------+-------------------------------------------+
+
+   The following additional characters may be appended to the flag to control
+   how the database is opened:
+
+   +---------+--------------------------------------------+
+   | Value   | Meaning                                    |
+   +=========+============================================+
+   | ``'f'`` | Open the database in fast mode.  Writes    |
+   |         | to the database will not be synchronized.  |
+   +---------+--------------------------------------------+
+   | ``'s'`` | Synchronized mode. This will cause changes |
+   |         | to the database to be immediately written  |
+   |         | to the file.                               |
+   +---------+--------------------------------------------+
+   | ``'u'`` | Do not lock database.                      |
+   +---------+--------------------------------------------+
+
+   Not all flags are valid for all versions of ``gdbm``.  The module constant
+   :const:`open_flags` is a string of supported flag characters.  The exception
+   :exc:`error` is raised if an invalid flag is specified.
+
+   The optional *mode* argument is the Unix mode of the file, used only when the
+   database has to be created.  It defaults to octal ``0666``.
+
+In addition to the dictionary-like methods, ``gdbm`` objects have the following
+methods:
+
+
+.. function:: firstkey()
+
+   It's possible to loop over every key in the database using this method  and the
+   :meth:`nextkey` method.  The traversal is ordered by ``gdbm``'s internal hash
+   values, and won't be sorted by the key values.  This method returns the starting
+   key.
+
+
+.. function:: nextkey(key)
+
+   Returns the key that follows *key* in the traversal.  The following code prints
+   every key in the database ``db``, without having to create a list in memory that
+   contains them all::
+
+      k = db.firstkey()
+      while k != None:
+          print k
+          k = db.nextkey(k)
+
+
+.. function:: reorganize()
+
+   If you have carried out a lot of deletions and would like to shrink the space
+   used by the ``gdbm`` file, this routine will reorganize the database.  ``gdbm``
+   will not shorten the length of a database file except by using this
+   reorganization; otherwise, deleted file space will be kept and reused as new
+   (key, value) pairs are added.
+
+
+.. function:: sync()
+
+   When the database has been opened in fast mode, this method forces any
+   unwritten data to be written to the disk.
+
+
+.. seealso::
+
+   Module :mod:`anydbm`
+      Generic interface to ``dbm``\ -style databases.
+
+   Module :mod:`whichdb`
+      Utility module used to determine the type of an existing database.
+