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64 lines
2.5 KiB
TeX
64 lines
2.5 KiB
TeX
\section{\module{dumbdbm} ---
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Portable DBM implementation}
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\declaremodule{standard}{dumbdbm}
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\modulesynopsis{Portable implementation of the simple DBM interface.}
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\index{databases}
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\begin{notice}
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The \module{dumbdbm} module is intended as a last resort fallback for
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the \refmodule{anydbm} module when no more robust module is available.
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The \module{dumbdbm} module is not written for speed and is not nearly as
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heavily used as the other database modules.
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\end{notice}
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The \module{dumbdbm} module provides a persistent dictionary-like interface
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which is written entirely in Python. Unlike other modules such as
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\refmodule{gdbm} and \refmodule{bsddb}, no external library is required. As
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with other persistent mappings, the keys and values must always be strings.
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The module defines the following:
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\begin{excdesc}{error}
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Raised on dumbdbm-specific errors, such as I/O errors. \exception{KeyError}
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is raised for general mapping errors like specifying an incorrect key.
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\end{excdesc}
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\begin{funcdesc}{open}{filename\optional{, flag\optional{, mode}}}
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Open a dumbdbm database and return a dumbdbm object. The \var{filename}
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argument is the basename of the database file (without any specific
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extensions). When a dumbdbm database is created, files with \file{.dat} and
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\file{.dir} extensions are created.
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The optional \var{flag} argument is currently ignored; the database is
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always opened for update, and will be created if it does not exist.
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The optional \var{mode} argument is the \UNIX{} mode of the file, used
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only when the database has to be created. It defaults to octal
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\code{0666} (and will be modified by the prevailing umask).
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\versionchanged[The \var{mode} argument was ignored in earlier
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versions]{2.2}
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\end{funcdesc}
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\begin{seealso}
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\seemodule{anydbm}{Generic interface to \code{dbm}-style databases.}
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\seemodule{dbm}{Similar interface to the DBM/NDBM library.}
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\seemodule{gdbm}{Similar interface to the GNU GDBM library.}
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\seemodule{shelve}{Persistence module which stores non-string data.}
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\seemodule{whichdb}{Utility module used to determine the type of an
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existing database.}
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\end{seealso}
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\subsection{Dumbdbm Objects \label{dumbdbm-objects}}
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In addition to the methods provided by the \class{UserDict.DictMixin} class,
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\class{dumbdbm} objects provide the following methods.
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\begin{methoddesc}{sync}{}
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Synchronize the on-disk directory and data files. This method is called by
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the \method{sync} method of \class{Shelve} objects.
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\end{methoddesc}
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