On-memory Tree Database — NDB

New in version 0.2.1.

NDB

class tokyo.cabinet.NDB

Example:

from tokyo.cabinet import *

ndb = NDB()

# store records
for key, value in [("foo", "hop"), ("bar", "step"), ("baz", "jump")]:
    ndb[key] = value

# retrieve one record
print(ndb["foo"])

# traverse records
for key in ndb:
    print(key, ndb[key])

Note

For all methods taking either a key argument or a pair (key, value), key and value must be either str (Python2) or bytes (Python3).

See also

API of On-memory Tree Database

len(ndb)

Return the number of records in the database ndb.

ndb[key]

Return the value of ndb‘s record corresponding to key. Raises KeyError if key is not in the database.

ndb[key] = value

Set ndb[key] to value.

del ndb[key]

Remove ndb[key] from ndb. Raises KeyError if key is not in the database.

key in ndb

Return True if ndb has a key key, else False.

key not in ndb

Equivalent to not key in ndb.

iter(ndb)

Return an iterator over the keys of the database.

clear()

Remove all records from the database.

get(key)

Return the value corresponding to key. Equivalent to ndb[key].

remove(key)

Delete a record from the database. Equivalent to del ndb[key].

put(key, value)

Store a record in the database. Equivalent to ndb[key] = value.

putkeep(key, value)

Store a record in the database, unlike the standard forms (ndb[key] = value or put()), this method raises KeyError if key is already in the database.

putcat(key, value)

Concatenate a value at the end of an existing one. If there is no corresponding record, a new record is stored.

iterkeys()

Return an iterator over the database’s keys.

New in version 0.6.1.

itervalues()

Return an iterator over the database’s values.

New in version 0.6.1.

iteritems()

Return an iterator over the database’s items ((key, value) pairs).

New in version 0.6.1.

searchkeys(prefix[, max])

Return a frozenset of keys starting with prefix. If given, max is the maximum number of keys to fetch, if omitted or specified as a negative value no limit is applied.

size

The size in bytes of the database.