Dump a database file to a pickle : Programming « Utility « Python






Dump a database file to a pickle


"""

PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2
--------------------------------------------

1. This LICENSE AGREEMENT is between the Python Software Foundation
("PSF"), and the Individual or Organization ("Licensee") accessing and
otherwise using this software ("Python") in source or binary form and
its associated documentation.

2. Subject to the terms and conditions of this License Agreement, PSF
hereby grants Licensee a nonexclusive, royalty-free, world-wide
license to reproduce, analyze, test, perform and/or display publicly,
prepare derivative works, distribute, and otherwise use Python
alone or in any derivative version, provided, however, that PSF's
License Agreement and PSF's notice of copyright, i.e., "Copyright (c)
2001, 2002, 2003, 2004 Python Software Foundation; All Rights Reserved"
are retained in Python alone or in any derivative version prepared
by Licensee.

3. In the event Licensee prepares a derivative work that is based on
or incorporates Python or any part thereof, and wants to make
the derivative work available to others as provided herein, then
Licensee hereby agrees to include in any such work a brief summary of
the changes made to Python.

4. PSF is making Python available to Licensee on an "AS IS"
basis.  PSF MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR
IMPLIED.  BY WAY OF EXAMPLE, BUT NOT LIMITATION, PSF MAKES NO AND
DISCLAIMS ANY REPRESENTATION OR WARRANTY OF MERCHANTABILITY OR FITNESS
FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF PYTHON WILL NOT
INFRINGE ANY THIRD PARTY RIGHTS.

5. PSF SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF PYTHON
FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS AS
A RESULT OF MODIFYING, DISTRIBUTING, OR OTHERWISE USING PYTHON,
OR ANY DERIVATIVE THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.

6. This License Agreement will automatically terminate upon a material
breach of its terms and conditions.

7. Nothing in this License Agreement shall be deemed to create any
relationship of agency, partnership, or joint venture between PSF and
Licensee.  This License Agreement does not grant permission to use PSF
trademarks or trade name in a trademark sense to endorse or promote
products or services of Licensee, or any third party.

8. By copying, installing or otherwise using Python, Licensee
agrees to be bound by the terms and conditions of this License
Agreement.
"""

#!/usr/bin/env python

"""
Synopsis: %(prog)s [-h|-g|-b|-r|-a] dbfile [ picklefile ]

Convert the database file given on the command line to a pickle
representation.  The optional flags indicate the type of the database:

    -a - open using anydbm
    -b - open as bsddb btree file
    -d - open as dbm file
    -g - open as gdbm file
    -h - open as bsddb hash file
    -r - open as bsddb recno file

The default is hash.  If a pickle file is named it is opened for write
access (deleting any existing data).  If no pickle file is named, the pickle
output is written to standard output.

"""

import getopt
try:
    import bsddb
except ImportError:
    bsddb = None
try:
    import dbm
except ImportError:
    dbm = None
try:
    import gdbm
except ImportError:
    gdbm = None
try:
    import anydbm
except ImportError:
    anydbm = None
import sys
try:
    import cPickle as pickle
except ImportError:
    import pickle

prog = sys.argv[0]

def usage():
    sys.stderr.write(__doc__ % globals())

def main(args):
    try:
        opts, args = getopt.getopt(args, "hbrdag",
                                   ["hash", "btree", "recno", "dbm",
                                    "gdbm", "anydbm"])
    except getopt.error:
        usage()
        return 1

    if len(args) == 0 or len(args) > 2:
        usage()
        return 1
    elif len(args) == 1:
        dbfile = args[0]
        pfile = sys.stdout
    else:
        dbfile = args[0]
        try:
            pfile = open(args[1], 'wb')
        except IOError:
            sys.stderr.write("Unable to open %s\n" % args[1])
            return 1

    dbopen = None
    for opt, arg in opts:
        if opt in ("-h", "--hash"):
            try:
                dbopen = bsddb.hashopen
            except AttributeError:
                sys.stderr.write("bsddb module unavailable.\n")
                return 1
        elif opt in ("-b", "--btree"):
            try:
                dbopen = bsddb.btopen
            except AttributeError:
                sys.stderr.write("bsddb module unavailable.\n")
                return 1
        elif opt in ("-r", "--recno"):
            try:
                dbopen = bsddb.rnopen
            except AttributeError:
                sys.stderr.write("bsddb module unavailable.\n")
                return 1
        elif opt in ("-a", "--anydbm"):
            try:
                dbopen = anydbm.open
            except AttributeError:
                sys.stderr.write("anydbm module unavailable.\n")
                return 1
        elif opt in ("-g", "--gdbm"):
            try:
                dbopen = gdbm.open
            except AttributeError:
                sys.stderr.write("gdbm module unavailable.\n")
                return 1
        elif opt in ("-d", "--dbm"):
            try:
                dbopen = dbm.open
            except AttributeError:
                sys.stderr.write("dbm module unavailable.\n")
                return 1
    if dbopen is None:
        if bsddb is None:
            sys.stderr.write("bsddb module unavailable - ")
            sys.stderr.write("must specify dbtype.\n")
            return 1
        else:
            dbopen = bsddb.hashopen

    try:
        db = dbopen(dbfile, 'r')
    except bsddb.error:
        sys.stderr.write("Unable to open %s.  " % dbfile)
        sys.stderr.write("Check for format or version mismatch.\n")
        return 1

    for k in db.keys():
        pickle.dump((k, db[k]), pfile, 1==1)

    db.close()
    pfile.close()

    return 0

if __name__ == "__main__":
    sys.exit(main(sys.argv[1:]))

           
       








Related examples in the same category

1.Indent Python code, giving block-closing comments
2.Load a pickle generated by db2pickle.py to a database
3.Assorted Tk-related subroutines used in Grail
4.Statement Coverage
5.Generate binary message catalog from textual translation description
6.Minimally patched to make it even more xgettext compatible
7.Check that all '.pyc' files exist and are up-to-date
8.Search Python (.py) files for future statements, and remove the features from such statements
9.A helper for analyzing PYTHONDUMPREFS output
10.Create Emacs TAGS file for Python modules
11.Massive identifier substitution on C source files
12.Fix the copyright notice in source files
13.Fix Python script(s) to reference the interpreter via /usr/bin/env python.
14.Add some standard cpp magic to a header file
15.Create Python codecs from Unicode mapping files
16.Transform gprof(1) output into useful HTML.
17.Translate #define's into Python assignments
18.Validate Python LaTeX formatting (Raymond Hettinger)
19.Change .py files to use 4-space indents.
20.Find dependencies between a bunch of Python modules.