85 lines
2.6 KiB
ReStructuredText
85 lines
2.6 KiB
ReStructuredText
:mod:`dumbdbm` --- Portable DBM implementation
|
|
==============================================
|
|
|
|
.. module:: dumbdbm
|
|
:synopsis: Portable implementation of the simple DBM interface.
|
|
|
|
.. note::
|
|
The :mod:`dumbdbm` module has been renamed to :mod:`dbm.dumb` in Python 3.
|
|
The :term:`2to3` tool will automatically adapt imports when converting your
|
|
sources to Python 3.
|
|
|
|
.. index:: single: databases
|
|
|
|
.. note::
|
|
|
|
The :mod:`dumbdbm` module is intended as a last resort fallback for the
|
|
:mod:`anydbm` module when no more robust module is available. The :mod:`dumbdbm`
|
|
module is not written for speed and is not nearly as heavily used as the other
|
|
database modules.
|
|
|
|
The :mod:`dumbdbm` module provides a persistent dictionary-like interface which
|
|
is written entirely in Python. Unlike other modules such as :mod:`gdbm` and
|
|
:mod:`bsddb`, no external library is required. As with other persistent
|
|
mappings, the keys and values must always be strings.
|
|
|
|
The module defines the following:
|
|
|
|
|
|
.. exception:: error
|
|
|
|
Raised on dumbdbm-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 dumbdbm database and return a dumbdbm object. The *filename* argument is
|
|
the basename of the database file (without any specific extensions). When a
|
|
dumbdbm database is created, files with :file:`.dat` and :file:`.dir` extensions
|
|
are created.
|
|
|
|
The optional *flag* argument is currently ignored; the database is always opened
|
|
for update, and will be created if it does not exist.
|
|
|
|
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`` (and will be modified
|
|
by the prevailing umask).
|
|
|
|
.. versionchanged:: 2.2
|
|
The *mode* argument was ignored in earlier versions.
|
|
|
|
|
|
.. seealso::
|
|
|
|
Module :mod:`anydbm`
|
|
Generic interface to ``dbm``\ -style databases.
|
|
|
|
Module :mod:`dbm`
|
|
Similar interface to the DBM/NDBM library.
|
|
|
|
Module :mod:`gdbm`
|
|
Similar interface to the GNU GDBM library.
|
|
|
|
Module :mod:`shelve`
|
|
Persistence module which stores non-string data.
|
|
|
|
Module :mod:`whichdb`
|
|
Utility module used to determine the type of an existing database.
|
|
|
|
|
|
.. _dumbdbm-objects:
|
|
|
|
Dumbdbm Objects
|
|
---------------
|
|
|
|
In addition to the methods provided by the :class:`UserDict.DictMixin` class,
|
|
:class:`dumbdbm` objects provide the following methods.
|
|
|
|
|
|
.. method:: dumbdbm.sync()
|
|
|
|
Synchronize the on-disk directory and data files. This method is called by the
|
|
:meth:`sync` method of :class:`Shelve` objects.
|
|
|