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<title>7.10 anydbm -- Generic access to DBM-style databases
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<H1><A NAME=
"SECTION0091000000000000000000">
7.10 <tt class=
"module">anydbm
</tt> --
Generic access to DBM-style databases
</A>
<A NAME=
"module-anydbm"></A>
<tt class=
"module">anydbm
</tt> is a generic interface to variants of the DBM
database --
<tt class=
"module"><a href=
"module-dbhash.html">dbhash
</a></tt><a id='l2h-
2780' xml:id='l2h-
2780'
></a> (requires
<tt class=
"module"><a href=
"module-bsddb.html">bsddb
</a></tt><a id='l2h-
2781' xml:id='l2h-
2781'
></a>),
<tt class=
"module"><a href=
"module-gdbm.html">gdbm
</a></tt><a id='l2h-
2782' xml:id='l2h-
2782'
></a>, or
<tt class=
"module"><a href=
"module-dbm.html">dbm
</a></tt><a id='l2h-
2783' xml:id='l2h-
2783'
></a>. If none of these modules is
installed, the slow-but-simple implementation in module
<tt class=
"module"><a href=
"module-dumbdbm.html">dumbdbm
</a></tt><a id='l2h-
2784' xml:id='l2h-
2784'
></a> will be used.
<dl><dt><table cellpadding=
"0" cellspacing=
"0"><tr valign=
"baseline">
<td><nobr><b><tt id='l2h-
2778' xml:id='l2h-
2778'
class=
"function">open
</tt></b>(
</nobr></td>
<td><var>filename
</var><big>[
</big><var>, flag
</var><big>[
</big><var>, mode
</var><big>]
</big><var></var><big>]
</big><var></var>)
</td></tr></table></dt>
Open the database file
<var>filename
</var> and return a corresponding object.
If the database file already exists, the
<tt class=
"module"><a href=
"module-whichdb.html">whichdb
</a></tt> 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
The optional
<var>flag
</var> argument can be
<code>'r'
</code> to open an existing database for reading only,
<code>'w'
</code> to open an existing database for reading and writing,
<code>'c'
</code> to create the database if it doesn't exist, or
<code>'n'
</code>, which will always create a new empty database. If not
specified, the default value is
<code>'r'
</code>.
The optional
<var>mode
</var> argument is the
<span class=
"Unix">Unix
</span> mode of the file, used
only when the database has to be created. It defaults to octal
<code>0666</code> (and will be modified by the prevailing umask).
<dl><dt><b><span class=
"typelabel">exception
</span> <tt id='l2h-
2779' xml:id='l2h-
2779'
class=
"exception">error
</tt></b></dt>
A tuple containing the exceptions that can be raised by each of the
supported modules, with a unique exception
<tt class=
"exception">anydbm.error
</tt> as
the first item -- the latter is used when
<tt class=
"exception">anydbm.error
</tt> is
The object returned by
<tt class=
"function">open()
</tt> supports most of the same
functionality as dictionaries; keys and their corresponding values can
be stored, retrieved, and deleted, and the
<tt class=
"method">has_key()
</tt> and
<tt class=
"method">keys()
</tt> methods are available. Keys and values must always be
<p class=
"heading">See Also:
</p>
<dl compact=
"compact" class=
"seemodule">
<dt>Module
<b><tt class=
"module"><a href=
"module-dbhash.html">dbhash
</a></tt>:
</b>
<dd>BSD
<code>db
</code> database interface.
<dl compact=
"compact" class=
"seemodule">
<dt>Module
<b><tt class=
"module"><a href=
"module-dbm.html">dbm
</a></tt>:
</b>
<dd>Standard
<span class=
"Unix">Unix
</span> database interface.
<dl compact=
"compact" class=
"seemodule">
<dt>Module
<b><tt class=
"module"><a href=
"module-dumbdbm.html">dumbdbm
</a></tt>:
</b>
<dd>Portable implementation of the
<code>dbm
</code> interface.
<dl compact=
"compact" class=
"seemodule">
<dt>Module
<b><tt class=
"module"><a href=
"module-gdbm.html">gdbm
</a></tt>:
</b>
<dd>GNU database interface, based on the
<code>dbm
</code> interface.
<dl compact=
"compact" class=
"seemodule">
<dt>Module
<b><tt class=
"module"><a href=
"module-shelve.html">shelve
</a></tt>:
</b>
<dd>General object persistence built on top of
the Python
<code>dbm
</code> interface.
<dl compact=
"compact" class=
"seemodule">
<dt>Module
<b><tt class=
"module"><a href=
"module-whichdb.html">whichdb
</a></tt>:
</b>
<dd>Utility module used to determine the type of an
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<span class=
"release-info">Release
2.4.2, documentation updated on
28 September
2005.
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