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<H1><A NAME="SECTION0091200000000000000000">
7.12 <tt class="module">whichdb</tt> --
Guess which DBM module created a database</A>
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<P>
<P>
The single function in this module attempts to guess which of the
several simple database modules available-<tt class='module'><a href="module-dbm.html" tppabs="http://www.python.org/doc/current/lib/module-dbm.html">dbm</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-dbhash.html" tppabs="http://www.python.org/doc/current/lib/module-dbhash.html">dbhash</a></tt>-should be used to open a
given file.
<P>
<dl><dt><b><a name='l2h-1724'><tt class='function'>whichdb</tt></a></b> (<var>filename</var>)
<dd>
Returns one of the following values: <code>None</code> if the file can't be
opened because it's unreadable or doesn't exist; the empty string
(<code>''</code>) if the file's format can't be guessed; or a string
containing the required module name, such as <code>'dbm'</code> or
<code>'gdbm'</code>.
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