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<H1><A NAME="SECTION009900000000000000000">
7.9 <tt class="module">anydbm</tt> --
Generic access to DBM-style databases</A>
</H1>
<P>
<P>
<tt class="module">anydbm</tt> is a generic interface to variants of the DBM
database -- <tt class='module'><a href="module-dbhash.html" tppabs="http://www.python.org/doc/current/lib/module-dbhash.html">dbhash</a></tt> (requires
<tt class='module'><a href="module-bsddb.html" tppabs="http://www.python.org/doc/current/lib/module-bsddb.html">bsddb</a></tt>),
<tt class='module'><a href="module-gdbm.html" tppabs="http://www.python.org/doc/current/lib/module-gdbm.html">gdbm</a></tt>, or
<tt class='module'><a href="module-dbm.html" tppabs="http://www.python.org/doc/current/lib/module-dbm.html">dbm</a></tt>. If none of these modules is
installed, the slow-but-simple implementation in module
<tt class='module'><a href="module-dumbdbm.html" tppabs="http://www.python.org/doc/current/lib/module-dumbdbm.html">dumbdbm</a></tt> will be used.
<P>
<dl><dt><b><a name='l2h-1704'><tt class='function'>open</tt></a></b> (<var>filename</var><big>[</big><var>, flag</var><big>[</big><var>, mode</var><big>]</big><big>]</big>)
<dd>
Open the database file <var>filename</var> and return a corresponding object.
<P>
If the database file already exists, the <tt class='module'><a href="module-whichdb.html" tppabs="http://www.python.org/doc/current/lib/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
used.
<P>
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>.
<P>
The optional <var>mode</var> argument is the Unix 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>
<P>
<dl><dt><b><a name='l2h-1705'><tt class='exception'>error</tt></a></b>
<dd>
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
raised.
</dl>
<P>
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
strings.
<P>
<div class='seealso'>
<p class='heading'><b>See Also:</b></p>
<dl compact class="seemodule">
<dt>Module <b><tt class='module'><a href="module-anydbm.html" tppabs="http://www.python.org/doc/current/lib/module-anydbm.html">anydbm</a></tt>:</b>
<dd>Generic interface to <code>dbm</code>-style databases.
</dl>
<dl compact class="seemodule">
<dt>Module <b><tt class='module'><a href="module-dbhash.html" tppabs="http://www.python.org/doc/current/lib/module-dbhash.html">dbhash</a></tt>:</b>
<dd>BSD <code>db</code> database interface.
</dl>
<dl compact class="seemodule">
<dt>Module <b><tt class='module'><a href="module-dbm.html" tppabs="http://www.python.org/doc/current/lib/module-dbm.html">dbm</a></tt>:</b>
<dd>Standard Unix database interface.
</dl>
<dl compact class="seemodule">
<dt>Module <b><tt class='module'><a href="module-dumbdbm.html" tppabs="http://www.python.org/doc/current/lib/module-dumbdbm.html">dumbdbm</a></tt>:</b>
<dd>Portable implementation of the <code>dbm</code> interface.
</dl>
<dl compact class="seemodule">
<dt>Module <b><tt class='module'><a href="module-gdbm.html" tppabs="http://www.python.org/doc/current/lib/module-gdbm.html">gdbm</a></tt>:</b>
<dd>GNU database interface, based on the <code>dbm</code> interface.
</dl>
<dl compact class="seemodule">
<dt>Module <b><tt class='module'><a href="module-shelve.html" tppabs="http://www.python.org/doc/current/lib/module-shelve.html">shelve</a></tt>:</b>
<dd>General object persistence built on top of
the Python <code>dbm</code> interface.
</dl>
<dl compact class="seemodule">
<dt>Module <b><tt class='module'><a href="module-whichdb.html" tppabs="http://www.python.org/doc/current/lib/module-whichdb.html">whichdb</a></tt>:</b>
<dd>Utility module used to determine the type of an
existing database.
</dl>
</div>
<P>
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