The shelve Module
The shelve module, shown in Example 10-3, uses the database handlers to implement persistent dictionaries. A shelve object uses string keys, but the value can be of any datatype, as long as it can be handled by the pickle module.
Example 10-3. Using the shelve Module
File: shelve-example-1.py import shelve db = shelve.open("database", "c") db["one"] = 1 db["two"] = 2 db["three"] = 3 db.close() db = shelve.open("database", "r") for key in db.keys(): print repr(key), repr(db[key]) 'one' 1 'three' 3 'two' 2
Example 10-4 shows how to use the shelve module with a given database driver.
Example 10-4. Using the shelve Module with a Given Database
File: shelve-example-3.py
import shelve
import gdbm
def gdbm_shelve(filename, flag="c"):
return shelve.Shelf(gdbm.open(filename, flag))
db = gdbm_shelve("dbfile")
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