Important

This documentation covers IPython versions 6.0 and higher. Beginning with version 6.0, IPython stopped supporting compatibility with Python versions lower than 3.3 including all versions of Python 2.7.

If you are looking for an IPython version compatible with Python 2.7, please use the IPython 5.x LTS release and refer to its documentation (LTS is the long term support release).

Module: core.events

Infrastructure for registering and firing callbacks on application events.

Unlike IPython.core.hooks, which lets end users set single functions to be called at specific times, or a collection of alternative methods to try, callbacks are designed to be used by extension authors. A number of callbacks can be registered for the same event without needing to be aware of one another.

The functions defined in this module are no-ops indicating the names of available events and the arguments which will be passed to them.

Note

This API is experimental in IPython 2.0, and may be revised in future versions.

1 Class

class IPython.core.events.EventManager(shell, available_events, print_on_error=True)

Bases: object

Manage a collection of events and a sequence of callbacks for each.

This is attached to InteractiveShell instances as an events attribute.

Note

This API is experimental in IPython 2.0, and may be revised in future versions.

__init__(shell, available_events, print_on_error=True)

Initialise the CallbackManager.

Parameters:

  • shell – The InteractiveShell instance

  • available_events – An iterable of names for callback events.

  • print_on_error – A boolean flag to set whether the EventManager will print a warning which a event errors.

register(event, function)

Register a new event callback.

Parameters:

  • event (str) – The event for which to register this callback.

  • function (callable) – A function to be called on the given event. It should take the same parameters as the appropriate callback prototype.

Raises:

  • TypeError – If function is not callable.

  • KeyError – If event is not one of the known events.

trigger(event, *args, **kwargs)

Call callbacks for event.

Any additional arguments are passed to all callbacks registered for this event. Exceptions raised by callbacks are caught, and a message printed.

unregister(event, function)

Remove a callback from the given event.

5 Functions

IPython.core.events.pre_execute()

Fires before code is executed in response to user/frontend action.

This includes comm and widget messages and silent execution, as well as user code cells.

IPython.core.events.pre_run_cell(info)

Fires before user-entered code runs.

Parameters:

info (ExecutionInfo) – An object containing information used for the code execution.

IPython.core.events.post_execute()

Fires after code is executed in response to user/frontend action.

This includes comm and widget messages and silent execution, as well as user code cells.

IPython.core.events.post_run_cell(result)

Fires after user-entered code runs.

Parameters:

result (ExecutionResult) – The object which will be returned as the execution result.

IPython.core.events.shell_initialized(ip)

Fires after initialisation of InteractiveShell.

This is before extensions and startup scripts are loaded, so it can only be set by subclassing.

Parameters:

ip (InteractiveShell) – The newly initialised shell.