Doc/lib/libgdbm.tex

   1 \section{Built-in Module \sectcode{gdbm}}
   2 \bimodindex{gdbm}
   3
   4 Gdbm provides python programs with an interface to the GNU \code{gdbm}
   5 database library.  Gdbm objects are of the mapping type, so they can be
   6 handled just like objects of the built-in \dfn{dictionary} type,
   7 except that keys and values are always strings, and printing a gdbm
   8 object doesn't print the keys and values.
   9
  10 The module is based on the Dbm module, modified to use GDBM instead.
  11
  12 The module defines the following constant and functions:
  13
  14 \renewcommand{\indexsubitem}{(in module gdbm)}
  15 \begin{excdesc}{error}
  16 Raised on gdbm-specific errors, such as I/O errors. \code{KeyError} is
  17 raised for general mapping errors like specifying an incorrect key.
  18 \end{excdesc}
  19
  20 \begin{funcdesc}{open}{filename\, rwmode\, filemode}
  21 Open a gdbm database and return a mapping object. \var{filename} is
  22 the name of the database file, \var{rwmode} is \code{'r'}, \code{'w'},
  23 \code{'c'}, or \code{'n'} for reader, writer (this also gives read
  24 access), create (writer, but create the database if it doesn't already
  25 exist) and newdb (which will always create a new database). Only one
  26 writer may open a gdbm file and many readers may open the file. Readers
  27 and writers cannot open the gdbm file at the same time. Note that the
  28 \code{GDBM_FAST} mode of opening the database is not supported. \var{filemode}
  29 is the \UNIX\ mode of the file, used only when a database is created.
  30 \end{funcdesc}