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Availability: Unix, Windows.
The bsddb module provides an interface to the Berkeley DB
library. Users can create hash, btree or record based library files
using the appropriate open call. Bsddb objects behave generally like
dictionaries. Keys and values must be strings, however, so to use
other objects as keys or to store other kinds of objects the user must
serialize them somehow, typically using marshal.dumps or pickle.dumps.
Starting with Python 2.3 the bsddb module requires the
Berkeley DB library version 3.2 or later (it is known to work with 3.2
through 4.3 at the time of this writing).
The following is a description of the legacy bsddb interface
compatible with the old Python bsddb module. For details about the more
modern Db and DbEnv object oriented interface see the above mentioned
pybsddb URL.
The bsddb module defines the following functions that create
objects that access the appropriate type of Berkeley DB file. The
first two arguments of each function are the same. For ease of
portability, only the first two arguments should be used in most
instances.
| hashopen( |
filename[, flag[,
mode[, bsize[,
ffactor[, nelem[,
cachesize[, hash[,
lorder]]]]]]]]) |
-
Open the hash format file named filename. Files never intended
to be preserved on disk may be created by passing
None as the
filename. The optional
flag identifies the mode used to open the file. It may be
"r" (read only), "w" (read-write) ,
"c" (read-write - create if necessary; the default) or
"n" (read-write - truncate to zero length). The other
arguments are rarely used and are just passed to the low-level
dbopen() function. Consult the Berkeley DB documentation
for their use and interpretation.
| btopen( |
filename[, flag[,
mode[, btflags[, cachesize[, maxkeypage[,
minkeypage[, pgsize[, lorder]]]]]]]]) |
-
Open the btree format file named filename. Files never intended
to be preserved on disk may be created by passing None as the
filename. The optional
flag identifies the mode used to open the file. It may be
"r" (read only), "w" (read-write),
"c" (read-write - create if necessary; the default) or
"n" (read-write - truncate to zero length). The other
arguments are rarely used and are just passed to the low-level dbopen
function. Consult the Berkeley DB documentation for their use and
interpretation.
| rnopen( |
filename[, flag[, mode[,
rnflags[, cachesize[, pgsize[, lorder[,
reclen[, bval[, bfname]]]]]]]]]) |
-
Open a DB record format file named filename. Files never intended
to be preserved on disk may be created by passing None as the
filename. The optional
flag identifies the mode used to open the file. It may be
"r" (read only), "w" (read-write),
"c" (read-write - create if necessary; the default) or
"n" (read-write - truncate to zero length). The other
arguments are rarely used and are just passed to the low-level dbopen
function. Consult the Berkeley DB documentation for their use and
interpretation.
Note:
Beginning in 2.3 some Unix versions of Python may have a bsddb185
module. This is present only to allow backwards compatibility with
systems which ship with the old Berkeley DB 1.85 database library. The
bsddb185 module should never be used directly in new code.
See Also:
- Module dbhash:
- DBM-style interface to the bsddb.
Release 2.4.5, documentation updated on 18 October 2006.
See About this document... for information on suggesting changes.
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