import shelve
d = shelve.open(filename) # open -- file may get suffix added by low-level
 # library
d[key] = data # store data at key (overwrites old data if
 # using an existing key)
data = d[key] # retrieve a COPY of data at key (raise KeyError if no
 # such key)
del d[key] # delete data stored at key (raises KeyError
 # if no such key)
flag = d.has_key(key) # true if the key exists
klist = d.keys() # a list of all existing keys (slow!)
# as d was opened WITHOUT writeback=True, beware:
d['xx'] = range(4) # this works as expected, but...
d['xx'].append(5) # *this doesn't!* -- d['xx'] is STILL range(4)!!!
# having opened d without writeback=True, you need to code carefully:
temp = d['xx'] # extracts the copy
temp.append(5) # mutates the copy
d['xx'] = temp # stores the copy right back, to persist it
# or, d=shelve.open(filename,writeback=True) would let you just code
# d['xx'].append(5) and have it work as expected, BUT it would also
# consume more memory and make the d.close() operation slower.
d.close() # close it

See Also:

Module anydbm :

Generic interface to dbm-style databases.

Module bsddb :

BSD db database interface.

Module dbhash :

Thin layer around the bsddb which provides an open function like the other database modules.

Module dbm :

Standard Unix database interface.

Module dumbdbm :

Portable implementation of the dbm interface.

Module gdbm :

GNU database interface, based on the dbm interface.

Module pickle :

Object serialization used by shelve.

Module cPickle :

High-performance version of pickle .