6.4.4 Get Information About Datastores

The oml.ds.dir function provides information about datastores.

The syntax of oml.ds.dir is the following:

oml.ds.dir(name=None, regex_match=False, dstype=’user’)

Use the name parameter to get information about a specific datastore.

Optionally, you can use the regex_match and dstype parameters to get information about datastores with certain characteristics. The valid arguments for dstype are the following:

Argument	Description
all	Lists all of the datastores to which the current user has the read privilege.
grant	Lists the datastores for which the current user has granted read privilege to other users.
granted	Lists the datastores for which other users have granted read privilege to the current user.
grantable	Lists the datastores that the current user can grant the read privilege to.
user	Lists the datastores created by current user.
private	Lists the datastores that the current user cannot grant the read privileges to.

The oml.ds.dir function returns a pandas.DataFrame object that contains different columns depending on which dstype argument you use. The following table lists the arguments and the columns returned for the values supplied.

dstype Argument	Columns in the DataFrame Returned
user private grantable	DSNAME, which contains the datastore name NOBJ, which contains the number of objects in the datastore DSIZE, which contains the size in bytes of each object in the datastore CDATE, which contains the creation date of the datastore DESCRIPTION, which contains the optional description of the datastore
all granted	All of the columns returned by the user, private, and grantable values, plus this additional column: DSOWNER, which contains the owner of the datastore
grant	DSNAME, which contains the datastore name GRANTEE, which contains the name of the user to which the read privilege to the datastore has been granted by the current session user

Example 6-16 Getting Information About Datastores

This example demonstrates using different combinations of arguments to the oml.ds.dir function. It demonstrates using oml.dir to list some or all of the datastores. For the creation of the datastores used in this example, see Example 6-14.

import oml

# Show all saved datastores.
oml.ds.dir(dstype="all")[['owner', 'datastore_name', 'object_count']]

# Show datastores to which other users have been granted the read 
# privilege.
oml.ds.dir(dstype="grant")

# Show datastores whose names match a pattern.
oml.ds.dir(name='pydata', regex_match=True)\
          [['datastore_name', 'object_count']]

Listing for This Example

>>> import oml
>>>
>>> # Show all saved datastores.
... oml.ds.dir(dstype="all")[['owner', 'datastore_name', 'object_count']]
     owner  datastore_name  object_count
0  OML_USER      ds_pydata             3
1  OML_USER     ds_pymodel             2
2  OML_USER   ds_wine_data             1
>>>
>>> # Show datastores to which other users have been granted the read 
>>> # privilege.
... oml.ds.dir(dstype="grant")
  datastore_name grantee
0     ds_pymodel  PUBLIC
>>>
>>> oml.ds.dir(name='pydata', regex_match=True)\
...           [['datastore_name', 'object_count']]
  datastore_name  object_count
0      ds_pydata             3