cpython/Doc/libanydbm.tex

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\section{Standard Modules \module{anydbm} and \module{dumbdbm}}
\label{module-anydbm}
\label{module-dumbdbm}
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\stmodindex{anydbm}
\stmodindex{dumbdbm}
\module{anydbm} is a generic interface to variants of the DBM
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database--DBM, GDBM, or dbhash. If none of these modules is
installed, the slow-but-simple implementation in module \module{dumbdbm}
will be used. Both modules provide the same interface:
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% not the best solution, but it's what you get for documenting both
% at the same time.
\setindexsubitem{(in modules anydbm, dumbdbm)}
\begin{funcdesc}{open}{filename\optional{, flag, mode}}
Open the database file \var{filename} and return a corresponding object.
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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).
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\end{funcdesc}
The object returned by \function{open()} supports most of the same
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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.
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Both modules also export the exception \exception{error}, which is
raised for various problems. The \exception{anydbm.error} exception
is simply a different name for the \exception{error} exception of the
underlying implementation module used.