atoti.session module#

class atoti.Session#

Holds a connection to the Java gateway.

__init__(*, name='Unnamed', app_extensions=None, authentication=None, branding=None, certificate_authority=None, client_certificate=None, extra_jars=(), https=None, i18n=None, java_options=(), jwt=None, logging=None, port=0, same_site=None, user_content_storage=None, **kwargs)#

Create a session.

Parameters

name (Optional[str]) –
The name of the session.

For a better prototyping experience in notebooks, creating a session with the same name as an already running session will close the latter one. Pass None to opt out of this behavior.
app_extensions (Optional[Mapping[str, Union[str, Path]]]) –
Mapping from the name of an extension (i.e. name property in their package.json) to the path of its dist directory.

Note

This requires the atoti-plus plugin.

Extensions can enhance the app in many ways such as:
- Adding new type of widgets.
- Attaching custom menu items or titlebar buttons to a set of widgets.
- Providing other React contexts to the components rendered by the app.
The app extension template can be used as a starting point.

See also

Existing extensions in atoti_plus.app_extension.
authentication (Union[BasicAuthenticationConfig, KerberosConfig, LdapConfig, OidcConfig, None]) –
The configuration to enable authentication on the session.

Note

This requires the atoti-plus plugin.

Users and roles are configured using atoti.Session.security.
branding (Optional[BrandingConfig]) – The config to customize some elements of the UI to change its appearance.
client_certificate (Optional[ClientCertificateConfig]) – The config to enable client certificate based authentication on the session.
extra_jars (Iterable[Union[str, Path]]) – The paths to the JARs to add to the classpath of the Java process when starting the session.
https (Optional[HttpsConfig]) – The config providing certificates to enable HTTPS on the session.
i18n (Optional[I18nConfig]) – The config to internationalize the session.
java_options (Iterable[str]) –
The additional options to pass when starting the Java process (e.g. for optimization or debugging purposes).

In particular, the -Xmx option can be set to increase the amount of RAM that the session can use.

If this option is not specified, the JVM default memory setting is used which is 25% of the machine memory.
jwt (Optional[JwtConfig]) – The config to set the key pair used to validate JWTs when authenticating with the session.
logging (Optional[LoggingConfig]) – The config describing how to handle session logs.
port (int) –
The port on which the session will be exposed.

Defaults to a random available port.
same_site (Optional[Literal[‘none’, ‘strict’]]) –
The value to use for the SameSite attribute of the HTTP cookie sent by the session when authentication is configured.

Note

This requires the atoti-plus plugin.

See https://web.dev/samesite-cookies-explained for more information.

Setting it to none requires the session to be served through HTTPS.

Defaults to lax.
user_content_storage (Union[Path, str, UserContentStorageConfig, None]) – The location of the database where the user content will be stored. The user content is what is not part of the data sources, such as the dashboards, widgets, and filters saved in the application. If a path to a directory is given, it will be created if needed. When None, the user content is kept in memory and is thus lost when the session is closed.

close()#

Close this session and free all the associated resources.

Return type: None

property closed: bool#

Return whether the session is closed or not.

Return type: bool

create_cube(base_table, name=None, *, mode='auto')#

Create a cube based on the passed table.

Parameters

base_table (Table) – The base table of the cube.
name (Optional[str]) – The name of the created cube. Defaults to the name of the base table.
mode (Literal[‘auto’, ‘manual’, ‘no_measures’]) –
The cube creation mode:
- auto: Creates hierarchies for every key column or non-numeric column of the table, and measures for every numeric column.
- manual: Does not create any hierarchy or measure (except from the count).
- no_measures: Creates the hierarchies like auto but does not create any measures.
For tables with hierarchized_columns specified, these will be converted into hierarchies regardless of the cube creation mode.

Example

>>> table = session.create_table(
...     "Table",
...     types={"id": tt.type.STRING, "value": tt.type.NULLABLE_DOUBLE},
... )
>>> cube_auto = session.create_cube(table)
>>> sorted(cube_auto.measures)
['contributors.COUNT', 'update.TIMESTAMP', 'value.MEAN', 'value.SUM']
>>> list(cube_auto.hierarchies)
[('Table', 'id')]
>>> cube_no_measures = session.create_cube(table, mode="no_measures")
>>> sorted(cube_no_measures.measures)
['contributors.COUNT', 'update.TIMESTAMP']
>>> list(cube_no_measures.hierarchies)
[('Table', 'id')]
>>> cube_manual = session.create_cube(table, mode="manual")
>>> sorted(cube_manual.measures)
['contributors.COUNT', 'update.TIMESTAMP']
>>> list(cube_manual.hierarchies)
[]

See also

query_mdx() for the roles of the parameters.

Return type: QueryAnalysis
Returns: An explanation containing a summary, global timings, and the query plan with all the retrievals.

export_translations_template(path)#

Export a template containing all translatable values in the session’s cubes.

Parameters: path (Union[str, Path]) – The path at which to write the template.
Return type: None

link(*, path='')#

Display a link to this session.

Clicking on the link will open it in a new browser tab.

Note

This method requires the atoti-jupyterlab plugin.

The extension will try to access the session through (in that order):

Jupyter Server Proxy if it is enabled.
f"{session_protocol}//{jupyter_server_hostname}:{session.port}" for atoti.Session and session.url for atoti_query.QuerySession.

Parameters: path (str) – The path to append to the session base URL. Defaults to the session home page.

Example

Pointing directly to an existing dashboard:

dashboard_id = "92i"
session.link(path=f"#/dashboard/{dashboard_id}")

Return type: Any

property logs_path: pathlib.Path#

Path to the session logs file.

Return type: Path

property name: Optional[str]#

Name of the session.

Return type: Optional[str]

property port: int#

Port on which the session is exposed.

Can be configured with atoti.Session()’s port parameter.

Return type: int

query_mdx(mdx, *, keep_totals=False, timeout=datetime.timedelta(seconds=30), mode='pretty', context={})#

Execute an MDX query and return its result as a pandas DataFrame.

Parameters

mdx (str) – The MDX SELECT query to execute. Regardless of the axes on which levels and measures appear in the MDX, the returned DataFrame will have all levels on rows and measures on columns.
keep_totals (bool) – Whether the resulting DataFrame should contain, if they are present in the query result, the grand total and subtotals. Totals can be useful but they make the DataFrame harder to work with since its index will have some empty values.
timeout (Union[int, timedelta]) – The amount of time the query execution can take before aborting it.
mode (Literal[‘pretty’, ‘raw’]) –
The query mode.
- "pretty" is best for queries returning small results:
  - A atoti_query.QueryResult will be returned and its rows will be sorted according to the level order.
- "raw" is best for benchmarks or large exports:
- A faster and more efficient endpoint reducing the data transfer from Java to Python will be used.
- A classic pandas.DataFrame will be returned.
- include_totals="True" will not be allowed.
- The Convert to Widget Below action provided by the atoti-jupyterlab plugin will not be available.
context (Mapping[str, Any]) – Context values to use when executing the query.

Example

>>> from datetime import date
>>> df = pd.DataFrame(
...     columns=["Country", "Date", "Price"],
...     data=[
...         ("China", date(2020, 3, 3), 410.0),
...         ("China", date(2020, 4, 4), 350.0),
...         ("France", date(2020, 1, 1), 480.0),
...         ("France", date(2020, 2, 2), 500.0),
...         ("France", date(2020, 3, 3), 400.0),
...         ("France", date(2020, 4, 4), 420.0),
...         ("India", date(2020, 1, 1), 360.0),
...         ("India", date(2020, 2, 2), 400.0),
...         ("UK", date(2020, 2, 2), 960.0),
...     ],
... )
>>> table = session.read_pandas(
...     df, keys=["Country", "Date"], table_name="Prices"
... )
>>> cube = session.create_cube(table)

This MDX:

>>> mdx = (
...     "SELECT"
...     "  NON EMPTY Hierarchize("
...     "    DrilldownLevel("
...     "      [Prices].[Country].[ALL].[AllMember]"
...     "    )"
...     "  ) ON ROWS,"
...     "  NON EMPTY Crossjoin("
...     "    [Measures].[Price.SUM],"
...     "    Hierarchize("
...     "      DrilldownLevel("
...     "        [Prices].[Date].[ALL].[AllMember]"
...     "      )"
...     "    )"
...     "  ) ON COLUMNS"
...     "  FROM [Prices]"
... )

would display this pivot table:

Country	Price.sum
Country	Total	2020-01-01	2020-02-02	2020-03-03	2020-04-04
Total	2,280.00	840.00	1,860.00	810.00	770.00
China	760.00			410.00	350.00
France	1,800.00	480.00	500.00	400.00	420.00
India	760.00	360.00	400.00
UK	960.00		960.00

but will return this DataFrame:

>>> session.query_mdx(mdx).sort_index()
                    Price.SUM
Date       Country
2020-01-01 France       480.0
           India        360.0
2020-02-02 France       500.0
           India        400.0
           UK           960.0
2020-03-03 China        410.0
           France       400.0
2020-04-04 China        350.0
           France       420.0

Return type: DataFrame

read_csv(path, *, keys=(), table_name=None, separator=None, encoding='utf-8', process_quotes=None, partitioning=None, types={}, columns={}, array_separator=None, hierarchized_columns=None, date_patterns={}, default_values={}, client_side_encryption=None)#

Read a CSV file into a table.

Parameters

path (Union[str, Path]) –
The path to the CSV file to load.

.gz, .tar.gz and .zip files containing compressed CSV(s) are also supported.

The path can also be a glob pattern (e.g. path/to/directory/**.*.csv).
keys (Iterable[str]) – The columns that will become keys of the table.
table_name (Optional[str]) – The name of the table to create. Required when path is a glob pattern. Otherwise, defaults to the final component of the path argument.
separator (Optional[str]) – The character separating the values of each line. the separator will be detected automatically.
encoding (str) – The encoding to use to read the CSV.
process_quotes (Optional[bool]) –
Whether double quotes should be processed to follow the official CSV specification:
- True:
  - Each field may or may not be enclosed in double quotes (however some programs, such as Microsoft Excel, do not use double quotes at all). If fields are not enclosed with double quotes, then double quotes may not appear inside the fields.
  - A double quote appearing inside a field must be escaped by preceding it with another double quote.
  - Fields containing line breaks, double quotes, and commas should be enclosed in double-quotes.
- False: all double-quotes within a field will be treated as any regular character, following Excel’s behavior. In this mode, it is expected that fields are not enclosed in double quotes. It is also not possible to have a line break inside a field.
- None: The behavior will be inferred from the first lines of the CSV file.
partitioning (Optional[str]) –
The description of how the data will be split across partitions of the table.

Joined tables can only use a sub-partitioning of the table referencing them.

Example

hash4(country) splits the data across 4 partitions based on the country column’s hash value.
types (Mapping[str, DataType]) – Types for some or all columns of the table. Types for non specified columns will be inferred from the first 1,000 lines.
columns (Mapping[str, str]) – Mapping from file column names to table column names. When the mapping is not empty, columns of the file absent from the mapping keys will not be loaded. Other parameters accepting column names expect to be passed table column names (i.e. values of this mapping) and not file column names.
array_separator (Optional[str]) – The character separating array elements. Setting it to a non-None value will parse all the columns containing this separator as arrays.
hierarchized_columns (Optional[Iterable[str]]) –
The list of columns which will automatically be converted into hierarchies no matter which creation mode is used for the cube.

The different behaviors based on the passed value are:
- None: all non-numeric columns are converted into hierarchies, depending on the cube’s creation mode.
- Empty collection: no columns are converted into hierarchies.
- Non-empty collection: only the columns in the collection will be converted into hierarchies.
For partial joins, regardless of the value of this parameter, hierarchies for the un-mapped key columns of the other table will be created.

See also

atoti.Table.join() for more information.
date_patterns (Mapping[str, str]) – A column name to date pattern mapping that can be used when the built-in date parsers fail to recognize the formatted dates in the passed files.
default_values (Mapping[str, Any]) –
Mapping from column name to the value to use when inserting a null value in the column.

The default value for nullable column is None and cannot be changed.
client_side_encryption (Optional[ClientSideEncryptionConfig]) – The client side encryption configuration to use when loading data.

Return type

Table

Returns

The created table holding the content of the CSV file(s).

read_numpy(array, *, columns, table_name, keys=(), partitioning=None, types={}, hierarchized_columns=None, default_values={})#

Read a NumPy 2D array into a new table.

Parameters

array (ndarray[Any, dtype[Any]]) – The NumPy 2D ndarray to read the data from.
columns (Sequence[str]) – The names to use for the table’s columns. They must be in the same order as the values in the NumPy array.
table_name (str) – The name of the table to create.
keys (Iterable[str]) – The columns that will become keys of the table.
partitioning (Optional[str]) –
The description of how the data will be split across partitions of the table.

Joined tables can only use a sub-partitioning of the table referencing them.

Example

hash4(country) splits the data across 4 partitions based on the country column’s hash value.
types (Mapping[str, DataType]) – Types for some or all columns of the table. Types for non specified columns will be inferred from numpy data types.
hierarchized_columns (Optional[Iterable[str]]) –
The list of columns which will automatically be converted into hierarchies no matter which creation mode is used for the cube.

The different behaviors based on the passed value are:
- None: all non-numeric columns are converted into hierarchies, depending on the cube’s creation mode.
- Empty collection: no columns are converted into hierarchies.
- Non-empty collection: only the columns in the collection will be converted into hierarchies.
For partial joins, regardless of the value of this parameter, hierarchies for the un-mapped key columns of the other table will be created.

See also

atoti.Table.join() for more information.
default_values (Mapping[str, Any]) –
Mapping from column name to the value to use when inserting a null value in the column.

The default value for nullable column is None and cannot be changed.

Return type

Table

Returns

The created table holding the content of the array.

read_pandas(dataframe, *, table_name, keys=(), partitioning=None, types={}, hierarchized_columns=None, default_values={}, **kwargs)#

Read a pandas DataFrame into a table.

All the named indices of the DataFrame are included into the table. Multilevel columns are flattened into a single string name.

Parameters

dataframe (DataFrame) – The DataFrame to load.
table_name (str) – The name of the table to create.
keys (Iterable[str]) – The columns that will become keys of the table.
partitioning (Optional[str]) –
The description of how the data will be split across partitions of the table.

Joined tables can only use a sub-partitioning of the table referencing them.

Example

hash4(country) splits the data across 4 partitions based on the country column’s hash value.
types (Mapping[str, DataType]) – Types for some or all columns of the table. Types for non specified columns will be inferred from pandas dtypes.
hierarchized_columns (Optional[Iterable[str]]) –
The list of columns which will automatically be converted into hierarchies no matter which creation mode is used for the cube.

The different behaviors based on the passed value are:
- None: all non-numeric columns are converted into hierarchies, depending on the cube’s creation mode.
- Empty collection: no columns are converted into hierarchies.
- Non-empty collection: only the columns in the collection will be converted into hierarchies.
For partial joins, regardless of the value of this parameter, hierarchies for the un-mapped key columns of the other table will be created.

See also

atoti.Table.join() for more information.
default_values (Mapping[str, Any]) –
Mapping from column name to the value to use when inserting a null value in the column.

The default value for nullable column is None and cannot be changed.

Return type

Table

Returns

The created table holding the content of the DataFrame.

read_parquet(path, *, keys=(), columns={}, table_name=None, partitioning=None, hierarchized_columns=None, default_values={}, client_side_encryption=None)#

Read a Parquet file into a table.

Parameters

path (Union[str, Path]) – The path to the Parquet file. If a path pointing to a directory is provided, all of the files with the .parquet extension in the directory will be loaded into the same table and, as such, they are all expected to share the same schema. The path can also be a glob pattern (e.g. path/to/directory/**.*.parquet).
keys (Iterable[str]) – The columns that will become keys of the table.
columns (Mapping[str, str]) – Mapping from file column names to table column names. When the mapping is not empty, columns of the file absent from the mapping keys will not be loaded. Other parameters accepting column names expect to be passed table column names (i.e. values of this mapping) and not file column names.
table_name (Optional[str]) – The name of the table to create. Required when path is a glob pattern. Otherwise, defaults to the final component of the path argument.
partitioning (Optional[str]) –
The description of how the data will be split across partitions of the table.

Joined tables can only use a sub-partitioning of the table referencing them.

Example

hash4(country) splits the data across 4 partitions based on the country column’s hash value.
hierarchized_columns (Optional[Iterable[str]]) –
The list of columns which will automatically be converted into hierarchies no matter which creation mode is used for the cube.

The different behaviors based on the passed value are:
- None: all non-numeric columns are converted into hierarchies, depending on the cube’s creation mode.
- Empty collection: no columns are converted into hierarchies.
- Non-empty collection: only the columns in the collection will be converted into hierarchies.
For partial joins, regardless of the value of this parameter, hierarchies for the un-mapped key columns of the other table will be created.

See also

atoti.Table.join() for more information.
default_values (Mapping[str, Any]) –
Mapping from column name to the value to use when inserting a null value in the column.

The default value for nullable column is None and cannot be changed.
client_side_encryption (Optional[ClientSideEncryptionConfig]) – The client side encryption configuration to use when loading data.

Return type

Table

Returns

The created table holding the content of the Parquet file(s).

read_spark(dataframe, *, table_name, keys=(), partitioning=None, hierarchized_columns=None, default_values={})#

Read a Spark DataFrame into a table.

Parameters

dataframe – The DataFrame to load.
table_name (str) – The name of the table to create.
keys (Iterable[str]) – The columns that will become keys of the table.
partitioning (Optional[str]) –
The description of how the data will be split across partitions of the table.

Joined tables can only use a sub-partitioning of the table referencing them.

Example

hash4(country) splits the data across 4 partitions based on the country column’s hash value.
hierarchized_columns (Optional[Iterable[str]]) –
The list of columns which will automatically be converted into hierarchies no matter which creation mode is used for the cube.

The different behaviors based on the passed value are:
- None: all non-numeric columns are converted into hierarchies, depending on the cube’s creation mode.
- Empty collection: no columns are converted into hierarchies.
- Non-empty collection: only the columns in the collection will be converted into hierarchies.
For partial joins, regardless of the value of this parameter, hierarchies for the un-mapped key columns of the other table will be created.

See also

atoti.Table.join() for more information.
default_values (Mapping[str, Any]) –
Mapping from column name to the value to use when inserting a null value in the column.

The default value for nullable column is None and cannot be changed.

Return type

Table

Returns

The created table holding the content of the DataFrame.

read_sql(query, *, url, table_name, driver=None, keys=(), partitioning=None, types={}, hierarchized_columns=None, default_values={})#

Create a table from the result of the passed SQL query.

Note

This method requires the atoti-sql plugin.

Parameters

query (str) – The result of this SQL query will be loaded into the table.
url (str) –
The JDBC connection URL of the database. The jdbc: prefix is optional but the database specific part (such as h2: or mysql:) is mandatory. For instance:
- h2:file:/home/user/database/file/path;USER=username;PASSWORD=passwd
- mysql://localhost:7777/example?user=username&password=passwd
- postgresql://postgresql.db.server:5430/example?user=username&password=passwd
More examples can be found here.
driver (Optional[str]) – The JDBC driver used to load the data. If None, the driver is inferred from the URL. Drivers can be found in the atoti_sql.drivers module.
table_name (str) – The name of the table to create.
keys (Iterable[str]) – The columns that will become keys of the table.
partitioning (Optional[str]) –
The description of how the data will be split across partitions of the table.

Joined tables can only use a sub-partitioning of the table referencing them.

Example

hash4(country) splits the data across 4 partitions based on the country column’s hash value.
types (Mapping[str, DataType]) – Types for some or all columns of the table. Types for non specified columns will be inferred from the SQL types.
hierarchized_columns (Optional[Iterable[str]]) –
The list of columns which will automatically be converted into hierarchies no matter which creation mode is used for the cube.

The different behaviors based on the passed value are:
- None: all non-numeric columns are converted into hierarchies, depending on the cube’s creation mode.
- Empty collection: no columns are converted into hierarchies.
- Non-empty collection: only the columns in the collection will be converted into hierarchies.
For partial joins, regardless of the value of this parameter, hierarchies for the un-mapped key columns of the other table will be created.

See also

atoti.Table.join() for more information.
default_values (Mapping[str, Any]) –
Mapping from column name to the value to use when inserting a null value in the column.

The default value for nullable column is None and cannot be changed.

Example

>>> table = session.read_sql(
...     "SELECT * FROM MYTABLE;",
...     url=f"h2:file:{RESOURCES}/h2-database;USER=root;PASSWORD=pass",
...     table_name="Cities",
...     keys=["ID"],
... )
>>> len(table)
5

Return type: Table

property scenarios: Sequence[str]#

Collection of source scenarios of the session.

Return type: Sequence[str]

property security: atoti_plus.security.Security#

Return type: Security

start_transaction(scenario_name='Base')#

Start a transaction to batch several table operations.

It is more efficient than doing each table operation one after the other.
It avoids possibly incorrect intermediate states (e.g. if loading some new data requires dropping existing rows first).

Note

Some operations are not allowed during a transaction:

Long-running operations such as atoti.Table.load_kafka().
Operations changing the structure of the session’s tables such as atoti.Table.join() or atoti.Session.read_parquet().
Operations not related to data loading or dropping such as defining a new measure.
Operations on parameter tables created from atoti.Cube.create_parameter_hierarchy_from_members() and atoti.Cube.create_parameter_simulation().
Operations on other source scenarios than the one the transaction is started on.

Parameters: scenario_name (str) – The name of the source scenario impacted by all the table operations inside the transaction.

Example

>>> df = pd.DataFrame(
...     columns=["City", "Price"],
...     data=[
...         ("Berlin", 150.0),
...         ("London", 240.0),
...         ("New York", 270.0),
...         ("Paris", 200.0),
...     ],
... )
>>> table = session.read_pandas(
...     df, keys=["City"], table_name="start_transaction example"
... )
>>> cube = session.create_cube(table)
>>> extra_df = pd.DataFrame(
...     columns=["City", "Price"],
...     data=[
...         ("Singapore", 250.0),
...     ],
... )
>>> with session.start_transaction():
...     table += ("New York", 100.0)
...     table.drop({"City": "Paris"})
...     table.load_pandas(extra_df)
...
>>> table.head().sort_index()
           Price
City
Berlin     150.0
London     240.0
New York   100.0
Singapore  250.0

Return type: Transaction

property tables: atoti.tables.Tables#

Tables of the session.

Return type: Tables

visualize(name=None)#

Display an atoti widget to explore the session interactively.

Note

This method requires the atoti-jupyterlab plugin.

The widget state will be stored in the cell metadata. This state should not have to be edited but, if desired, it can be found in JupyterLab by opening the “Notebook tools” sidebar and expanding the “Advanced Tools” section.

Parameters: name (Optional[str]) – The name to give to the widget.
Return type: None

wait()#

Wait for the underlying server subprocess to terminate.

This will prevent the Python process to exit.

Return type: None