Use the Athena notebook editor

You manage your notebooks in the Athena notebook explorer and edit and run them in sessions using the Athena notebook editor. You can configure DPU usage for your notebook sessions according to your requirements.

When you stop a notebook, you terminate the associated session. All files are saved, but changes underway in declared variables, functions and classes are lost. When you restart the notebook, Athena reloads the notebook files and you can run your code again.

The Athena notebook editor is an interactive environment for writing and running code. The following sections describe the features of the environment.

Understand notebook sessions and calculations

Each notebook is associated with a single Python kernel and runs Python code. A notebook can have one or more cells that contain commands. To run the cells in a notebook, you first create a session for the notebook. Sessions keep track of the variables and state of notebooks.

Running a cell in a notebook means running a calculation in the current session. Calculations progress the state of the notebook and may perform tasks like reading from Amazon S3 or writing to other data stores. As long as a session is running, calculations use and modify the state that is maintained for the notebook.

When you no longer need the state, you can end a session. When you end a session, the notebook remains, but the variables and other state information are destroyed. If you need to work on multiple projects at the same time, you can create a session for each project, and the sessions will be independent from each other.

Sessions have dedicated compute capacity, measured in DPU. When you create a session, you can assign the session a number of DPUs. Different sessions can have different capacities depending on the requirements of the task.

Switch between command mode and edit mode

The notebook editor has a modal user interface: an edit mode for entering text into a cell, and a command mode for issuing commands to the editor itself like copy, paste, or run.

To use edit mode and command mode, you can perform the following tasks:

• To enter edit mode, press ENTER, or choose a cell. When a cell is in edit mode, the cell has a green left margin.

• To enter command mode, press ESC, or click outside of a cell. Note that commands typically apply only to the currently selected cell, not to all cells. When the editor is in command mode, the cell has a blue left margin.

• In command mode, you can use keyboard shortcuts and the menu above the editor, but not enter text into individual cells.

• To select a cell, choose the cell.

• To select all cells, press Ctrl+A (Windows) or Cmd+A (Mac).

Use actions in the notebook editor menu

The icons in the menu at the top of the notebook editor offer the following options:

• Save – Saves the current state of the notebook.

• Insert cell below – Adds a new (empty) cell below the currently selected one.

• Cut selected cells – Removes the selected cell from its current location and copies the cell to memory.

• Copy selected cells – Copies the selected cell to memory.

• Paste cells below – Pastes the copied cell below the current cell.

• Move selected cells up – Moves the current cell above the cell above.

• Move selected cells down – Moves the current cell below the cell below.

• Run – Runs the current (selected) cell. The output displays immediately below the current cell.

• Run all – Runs all cells in the notebook. The output for each cell displays immediately below the cell.

• Stop (Interrupt the kernel) – Stops the current notebook by interrupting the kernel.

• Format option – Selects the cell format, which can be one of the following:

  • Code – Use for Python code (the default).

  • Markdown – Use for entering text in GitHub-style markdown format. To render the markdown, run the cell.

  • Raw NBConvert – Use for entering text in unmodified form. Cells marked as Raw NBConvert can be converted into a different format like HTML by the Jupyter nbconvert command line tool.

• Heading – Use to change the heading level of the cell.

• Command palette – Contains Jupyter notebook commands and their keyboard shortcuts. For more information about the keyboard shortcuts, see the sections later in this document.

• Session – Use options in this menu to view the details for a session, edit session parameters, or terminate the session.

Use command mode keyboard shortcuts for productivity

The following are some common notebook editor command mode keyboard shortcuts. These shortcuts are available after pressing ESC to enter command mode. To see a full list of commands available in the editor, press ESC + H.

Key	Action
1 - 6	Change the cell type to markdown and set the heading level to the number typed
a	Create a cell above the current cell
b	Create a cell below the current cell
c	Copy the current cell to memory
d d	Delete the current cell
h	Display the keyboard shortcut help screen
j	Go one cell down
k	Go one cell up
m	Change the current cell format to markdown
r	Change the current cell format to raw
s	Save the notebook
v	Paste memory contents under the current cell
x	Cut the selected cell or cells
y	Change the cell format to code
z	Undo
Ctrl+Enter	Run the current cell and enter command mode
Shift+Enter or Alt+Enter	Run the current cell and create a new cell below the output, and enter the new cell in edit mode
Space	Page down
Shift+Space	Page up
Shift + L	Toggle the visibility of line numbers in cells

Customize command mode shortcuts

The notebook editor has an option to customize command mode keyboard shortcuts.

To edit command mode shortcuts

1. From the notebook editor menu, the choose the Command palette.

2. From the command palette, choose the Edit command mode keyboard shortcuts command.

3. Use the Edit command mode shortcuts interface to map or remap commands that you want to the keyboard.

   To see instructions for editing command mode shortcuts, scroll to the bottom of the Edit command mode shortcuts screen.

For information about using magic commands in Athena for Apache Spark, see Use magic commands.

Topics

• Use magic commands