1 :mod:`dumbdbm` --- Portable DBM implementation 2 ============================================== 3 4 .. module:: dumbdbm 5 :synopsis: Portable implementation of the simple DBM interface. 6 7 .. note:: 8 The :mod:`dumbdbm` module has been renamed to :mod:`dbm.dumb` in Python 3. 9 The :term:`2to3` tool will automatically adapt imports when converting your 10 sources to Python 3. 11 12 .. index:: single: databases 13 14 .. note:: 15 16 The :mod:`dumbdbm` module is intended as a last resort fallback for the 17 :mod:`anydbm` module when no more robust module is available. The :mod:`dumbdbm` 18 module is not written for speed and is not nearly as heavily used as the other 19 database modules. 20 21 The :mod:`dumbdbm` module provides a persistent dictionary-like interface which 22 is written entirely in Python. Unlike other modules such as :mod:`gdbm` and 23 :mod:`bsddb`, no external library is required. As with other persistent 24 mappings, the keys and values must always be strings. 25 26 The module defines the following: 27 28 29 .. exception:: error 30 31 Raised on dumbdbm-specific errors, such as I/O errors. :exc:`KeyError` is 32 raised for general mapping errors like specifying an incorrect key. 33 34 35 .. function:: open(filename[, flag[, mode]]) 36 37 Open a dumbdbm database and return a dumbdbm object. The *filename* argument is 38 the basename of the database file (without any specific extensions). When a 39 dumbdbm database is created, files with :file:`.dat` and :file:`.dir` extensions 40 are created. 41 42 The optional *flag* argument is currently ignored; the database is always opened 43 for update, and will be created if it does not exist. 44 45 The optional *mode* argument is the Unix mode of the file, used only when the 46 database has to be created. It defaults to octal ``0666`` (and will be modified 47 by the prevailing umask). 48 49 .. versionchanged:: 2.2 50 The *mode* argument was ignored in earlier versions. 51 52 In addition to the dictionary-like methods, ``dumbdm`` objects 53 provide the following method: 54 55 56 .. function:: close() 57 58 Close the ``dumbdm`` database. 59 60 61 .. seealso:: 62 63 Module :mod:`anydbm` 64 Generic interface to ``dbm``\ -style databases. 65 66 Module :mod:`dbm` 67 Similar interface to the DBM/NDBM library. 68 69 Module :mod:`gdbm` 70 Similar interface to the GNU GDBM library. 71 72 Module :mod:`shelve` 73 Persistence module which stores non-string data. 74 75 Module :mod:`whichdb` 76 Utility module used to determine the type of an existing database. 77 78 79 .. _dumbdbm-objects: 80 81 Dumbdbm Objects 82 --------------- 83 84 In addition to the methods provided by the :class:`UserDict.DictMixin` class, 85 :class:`~dumbdbm.dumbdbm` objects provide the following methods. 86 87 88 .. method:: dumbdbm.sync() 89 90 Synchronize the on-disk directory and data files. This method is called by the 91 :meth:`sync` method of :class:`Shelve` objects. 92 93
