mirror of
https://github.com/python/cpython.git
synced 2024-11-28 16:45:42 +01:00
97 lines
3.7 KiB
TeX
97 lines
3.7 KiB
TeX
\section{\module{anydbm} ---
|
|
Generic access to DBM-style databases}
|
|
|
|
\declaremodule{standard}{anydbm}
|
|
\modulesynopsis{Generic interface to DBM-style database modules.}
|
|
|
|
|
|
\module{anydbm} is a generic interface to variants of the DBM
|
|
database --- \refmodule{dbhash}\refstmodindex{dbhash} (requires
|
|
\refmodule{bsddb}\refbimodindex{bsddb}),
|
|
\refmodule{gdbm}\refbimodindex{gdbm}, or
|
|
\refmodule{dbm}\refbimodindex{dbm}. If none of these modules is
|
|
installed, the slow-but-simple implementation in module
|
|
\refmodule{dumbdbm}\refstmodindex{dumbdbm} will be used.
|
|
|
|
\begin{funcdesc}{open}{filename\optional{, flag\optional{, mode}}}
|
|
Open the database file \var{filename} and return a corresponding object.
|
|
|
|
If the database file already exists, the \refmodule{whichdb} module is
|
|
used to determine its type and the appropriate module is used; if it
|
|
does not exist, the first module listed above that can be imported is
|
|
used.
|
|
|
|
The optional \var{flag} argument can be
|
|
\code{'r'} to open an existing database for reading only,
|
|
\code{'w'} to open an existing database for reading and writing,
|
|
\code{'c'} to create the database if it doesn't exist, or
|
|
\code{'n'}, which will always create a new empty database. If not
|
|
specified, the default value is \code{'r'}.
|
|
|
|
The optional \var{mode} argument is the \UNIX{} mode of the file, used
|
|
only when the database has to be created. It defaults to octal
|
|
\code{0666} (and will be modified by the prevailing umask).
|
|
\end{funcdesc}
|
|
|
|
\begin{excdesc}{error}
|
|
A tuple containing the exceptions that can be raised by each of the
|
|
supported modules, with a unique exception \exception{anydbm.error} as
|
|
the first item --- the latter is used when \exception{anydbm.error} is
|
|
raised.
|
|
\end{excdesc}
|
|
|
|
The object returned by \function{open()} supports most of the same
|
|
functionality as dictionaries; keys and their corresponding values can
|
|
be stored, retrieved, and deleted, and the \method{has_key()} and
|
|
\method{keys()} methods are available. Keys and values must always be
|
|
strings.
|
|
|
|
|
|
\begin{seealso}
|
|
\seemodule{dbhash}{BSD \code{db} database interface.}
|
|
\seemodule{dbm}{Standard \UNIX{} database interface.}
|
|
\seemodule{dumbdbm}{Portable implementation of the \code{dbm} interface.}
|
|
\seemodule{gdbm}{GNU database interface, based on the \code{dbm} interface.}
|
|
\seemodule{shelve}{General object persistence built on top of
|
|
the Python \code{dbm} interface.}
|
|
\seemodule{whichdb}{Utility module used to determine the type of an
|
|
existing database.}
|
|
\end{seealso}
|
|
|
|
|
|
\section{\module{dumbdbm} ---
|
|
Portable DBM implementation}
|
|
|
|
\declaremodule{standard}{dumbdbm}
|
|
\modulesynopsis{Portable implementation of the simple DBM interface.}
|
|
|
|
|
|
A simple and slow database implemented entirely in Python. This
|
|
should only be used when no other DBM-style database is available.
|
|
|
|
|
|
\begin{funcdesc}{open}{filename\optional{, flag\optional{, mode}}}
|
|
Open the database file \var{filename} and return a corresponding
|
|
object. The \var{flag} argument, used to control how the database is
|
|
opened in the other DBM implementations, is ignored in
|
|
\module{dumbdbm}; the database is always opened for update, and will
|
|
be created if it does not exist.
|
|
|
|
The optional \var{mode} argument is the \UNIX{} mode of the file, used
|
|
only when the database has to be created. It defaults to octal
|
|
\code{0666} (and will be modified by the prevailing umask).
|
|
\versionchanged[The \var{mode} argument was ignored in earlier
|
|
versions]{2.2}
|
|
\end{funcdesc}
|
|
|
|
\begin{excdesc}{error}
|
|
Raised for errors not reported as \exception{KeyError} errors.
|
|
\end{excdesc}
|
|
|
|
|
|
\begin{seealso}
|
|
\seemodule{anydbm}{Generic interface to \code{dbm}-style databases.}
|
|
\seemodule{whichdb}{Utility module used to determine the type of an
|
|
existing database.}
|
|
\end{seealso}
|