The dbhash module provides a function to open databases using
the BSD db library. This module mirrors the interface of the
other Python database modules that provide access to DBM-style
databases. The bsddbmodule is required
to use dbhash.
Open a db database and return the database object. The
path argument is the name of the database file.
The flag argument can be
'r' (the default), 'w',
'c' (which creates the database if it doesn't exist), or
'n' (which always creates a new empty database).
For platforms on which the BSD db library supports locking,
an "l" can be appended to indicate that locking should be
used.
The optional mode parameter is used to indicate the Unix
permission bits that should be set if a new database must be
created; this will be masked by the current umask value for the
process.