6.4.5 Get Information About Datastore Objects

The oml.ds.describe function provides information about the objects in a datastore.

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

oml.ds.describe(name, owner=None))

The name argument is a string that specifies the name of a datastore.

The owner argument is a string that specifies the owner of the datastore or None (the default). If you do not specify the owner, then the function returns information about the datastore if it is owned by the current user.

The oml.ds.describe function returns a pandas.DataFrame object, each row of which represents an object in the datastore. The columns of the DataFrame are the following:

• object_name, which specifies the name of the object

• class, which specifies the class of the object

• size, which specifies the size of the object in bytes

• length, which specifies the length of the object

• row_count, which specifies the rows of the object

• col_count, which specifies the columns of the object

This function raises a ValueError if the following occur:

• The current user is not the owner of the datastore and has not been granted read privilege for the datastore.

• The datastore does not exist.

Example 6-17 Getting Information About Datastore Objects

This example demonstrates the using the oml.ds.describe function. For the creation of the datastore used in this example, see Example 6-14.

import oml

# Describe the contents of the ds_pydata datastore.
oml.ds.describe(name='ds_pydata')
oml.ds.describe(name="ds_pydata")[['object_name', 'class']]

Listing for This Example

>>> import oml
>>>
>>> # Describe the contents of the ds_pydata datastore.
... oml.ds.describe(name='ds_pydata')
    object_name          class   size  length  row_count  col_count
0    oml_boston  oml.DataFrame   1073     506        506         14
1  oml_diabetes  oml.DataFrame    964     442        442         11
2          wine          Bunch  24177       5          1          5
>>> oml.ds.describe(name="ds_pydata")[['object_name', 'class']]
    object_name          class
0    oml_boston  oml.DataFrame
1  oml_diabetes  oml.DataFrame
2          wine          Bunch