mirror of
https://github.com/Sneed-Group/Poodletooth-iLand
synced 2024-12-24 20:22:33 -06:00
85 lines
2.6 KiB
Python
85 lines
2.6 KiB
Python
"""Generic interface to all dbm clones.
|
|
|
|
Instead of
|
|
|
|
import dbm
|
|
d = dbm.open(file, 'w', 0666)
|
|
|
|
use
|
|
|
|
import anydbm
|
|
d = anydbm.open(file, 'w')
|
|
|
|
The returned object is a dbhash, gdbm, dbm or dumbdbm object,
|
|
dependent on the type of database being opened (determined by whichdb
|
|
module) in the case of an existing dbm. If the dbm does not exist and
|
|
the create or new flag ('c' or 'n') was specified, the dbm type will
|
|
be determined by the availability of the modules (tested in the above
|
|
order).
|
|
|
|
It has the following interface (key and data are strings):
|
|
|
|
d[key] = data # store data at key (may override data at
|
|
# existing key)
|
|
data = d[key] # retrieve data at key (raise KeyError if no
|
|
# such key)
|
|
del d[key] # delete data stored at key (raises KeyError
|
|
# if no such key)
|
|
flag = key in d # true if the key exists
|
|
list = d.keys() # return a list of all existing keys (slow!)
|
|
|
|
Future versions may change the order in which implementations are
|
|
tested for existence, and add interfaces to other dbm-like
|
|
implementations.
|
|
"""
|
|
|
|
class error(Exception):
|
|
pass
|
|
|
|
_names = ['dbhash', 'gdbm', 'dbm', 'dumbdbm']
|
|
_errors = [error]
|
|
_defaultmod = None
|
|
|
|
for _name in _names:
|
|
try:
|
|
_mod = __import__(_name)
|
|
except ImportError:
|
|
continue
|
|
if not _defaultmod:
|
|
_defaultmod = _mod
|
|
_errors.append(_mod.error)
|
|
|
|
if not _defaultmod:
|
|
raise ImportError, "no dbm clone found; tried %s" % _names
|
|
|
|
error = tuple(_errors)
|
|
|
|
def open(file, flag='r', mode=0666):
|
|
"""Open or create database at path given by *file*.
|
|
|
|
Optional argument *flag* can be 'r' (default) for read-only access, 'w'
|
|
for read-write access of an existing database, 'c' for read-write access
|
|
to a new or existing database, and 'n' for read-write access to a new
|
|
database.
|
|
|
|
Note: 'r' and 'w' fail if the database doesn't exist; 'c' creates it
|
|
only if it doesn't exist; and 'n' always creates a new database.
|
|
"""
|
|
|
|
# guess the type of an existing database
|
|
from whichdb import whichdb
|
|
result=whichdb(file)
|
|
if result is None:
|
|
# db doesn't exist
|
|
if 'c' in flag or 'n' in flag:
|
|
# file doesn't exist and the new
|
|
# flag was used so use default type
|
|
mod = _defaultmod
|
|
else:
|
|
raise error, "need 'c' or 'n' flag to open new db"
|
|
elif result == "":
|
|
# db type cannot be determined
|
|
raise error, "db type could not be determined"
|
|
else:
|
|
mod = __import__(result)
|
|
return mod.open(file, flag, mode)
|