blob: a7d67989bf6ca64fdefed880ddb7df677d87c264 [file] [log] [blame]
Guido van Rossum51a6c901997-05-09 02:23:45 +00001\section{Standard Modules \sectcode{anydbm} and \sectcode{dumbdbm}}
Guido van Rossum571391b1997-04-03 22:41:49 +00002\stmodindex{anydbm}
3\stmodindex{dumbdbm}
4
5\code{anydbm} is a generic interface to variants of the DBM
6database--DBM, GDBM, or dbhash. If none of these modules is
Guido van Rossum51a6c901997-05-09 02:23:45 +00007installed, the slow-but-simple implementation in module \code{dumbdbm}
8will be used. Both modules provide the same interface:
Guido van Rossum571391b1997-04-03 22:41:49 +00009
10\begin{funcdesc}{open}{filename\optional{\, flag\, mode}}
11Open the database file \var{filename} and return a corresponding object.
12The optional \var{flag} argument can be
13\code{'r'} to open an existing database for reading only,
14\code{'w'} to open an existing database for reading and writing,
15\code{'c'} to create the database if it doesn't exist, or
16\code{'n'}, which will always create a new empty database. If not
17specified, the default value is \code{'r'}.
18
19The optional \var{mode} argument is the \UNIX{} mode of the file, used
20only when the database has to be created. It defaults to octal
Guido van Rossum51a6c901997-05-09 02:23:45 +000021\code{0666} (and will be modified by the prevailing umask).
Guido van Rossum571391b1997-04-03 22:41:49 +000022\end{funcdesc}
23
Guido van Rossum51a6c901997-05-09 02:23:45 +000024The object returned by \code{open()} supports most of the same
Guido van Rossum571391b1997-04-03 22:41:49 +000025functionality as dictionaries; keys and their corresponding values can
26be stored, retrieved, and deleted, and the \code{has_key()} and
Guido van Rossum51a6c901997-05-09 02:23:45 +000027\code{keys()} methods are available. Keys and values must always be
28strings.
Guido van Rossum571391b1997-04-03 22:41:49 +000029
Guido van Rossum51a6c901997-05-09 02:23:45 +000030Both modules also export the exception \code{error}, which is raised
31for various problems. The \code{anydbm.error} exception is simply a
32different name for the \code{error} exception of the underlying
33implementation module used.