clusterlib.storage.sqlite3_loads¶

clusterlib.storage.sqlite3_loads(file_name, key=None, timeout=7200.0)¶

Load value with key from sqlite3 stored at fname.

In order to improve performance, it’s advised to query the database using as many keys as possible at once. Otherwise by calling this function repeatedly, you might run into the SQlite lock timeout.

Parameters:	file_name : str Path to the sqlite database. key : str or list of str or None, optional (default=None) Key or list of keys used when the value was stored. If key is None, all key value pairs are returned from the database. timeout : float, optional (default=7200.0) The timeout parameter specifies how long the connection should wait for the lock to go away until raising an exception.
Returns:	out : dict Return a dict where each key point is associated to the stored object. If a key from key is missing in the sqlite3, then there is no entry in out for this key. If there is no sqlite3 database at file_name, then an empty dictionary is returned.

Examples

Here, we generate a temporary sqlite3 database, dump then load some data from it.

>>> from tempfile import NamedTemporaryFile
>>> from clusterlib.storage import sqlite3_dumps
>>> from clusterlib.storage import sqlite3_loads
>>> with NamedTemporaryFile() as fhandle:
...     sqlite3_dumps({"3": 3, "2": 5}, fhandle.name)
...     out = sqlite3_loads(fhandle.name, key=["7", "3"])
...     print(out['3'])
...     print("7" in out)  # "7" is not in the database
3
False

It’s also possible to get all key-value pairs from the database without specifying the keys.

>>> with NamedTemporaryFile() as fhandle:
...     sqlite3_dumps({'first': 1}, fhandle.name)
...     out = sqlite3_loads(fhandle.name)
...     print(out['first'])
1