# Module: `parallel.error`

Classes and functions for kernel related errors and exceptions.

Inheritance diagram:

Authors:

- Brian Granger
- Min RK

## 14 Classes

class `IPython.parallel.error.``IPythonError`

  Bases: `exceptions.Exception`

  Base exception that all of our exceptions inherit from.

  This can be raised by code that doesn’t have any more specific information.

class `IPython.parallel.error.``KernelError`

  Bases: `IPython.parallel.error.IPythonError`

class `IPython.parallel.error.``EngineError`

  Bases: `IPython.parallel.error.KernelError`

class `IPython.parallel.error.``NoEnginesRegistered`

  Bases: `IPython.parallel.error.KernelError`

class `IPython.parallel.error.``TaskAborted`

  Bases: `IPython.parallel.error.KernelError`

class `IPython.parallel.error.``TaskTimeout`

  Bases: `IPython.parallel.error.KernelError`

class `IPython.parallel.error.``TimeoutError`

  Bases: `IPython.parallel.error.KernelError`

class `IPython.parallel.error.``UnmetDependency`

  Bases: `IPython.parallel.error.KernelError`

class `IPython.parallel.error.``ImpossibleDependency`

  Bases: `IPython.parallel.error.UnmetDependency`

class `IPython.parallel.error.``DependencyTimeout`

  Bases: `IPython.parallel.error.ImpossibleDependency`

class `IPython.parallel.error.``InvalidDependency`

  Bases: `IPython.parallel.error.ImpossibleDependency`

class `IPython.parallel.error.``RemoteError`(ename, evalue, traceback, engine_info=None)

  Bases: `IPython.parallel.error.KernelError`

  Error raised elsewhere

  `__init__`(ename, evalue, traceback, engine_info=None)
  `print_traceback`(excid=None)

    print my traceback

  `render_traceback`()

    render traceback to a list of lines

class `IPython.parallel.error.``TaskRejectError`

  Bases: `IPython.parallel.error.KernelError`

  Exception to raise when a task should be rejected by an engine.

  This exception can be used to allow a task running on an engine to test if the engine (or the user’s namespace on the engine) has the needed task dependencies. If not, the task should raise this exception. For the task to be retried on another engine, the task should be created with the retries argument > 1.

  The advantage of this approach over our older properties system is that tasks have full access to the user’s namespace on the engines and the properties don’t have to be managed or tested by the controller.

class `IPython.parallel.error.``CompositeError`(message, elist)

  Bases: `IPython.parallel.error.RemoteError`

  Error for representing possibly multiple errors on engines

  `__init__`(message, elist)
  `render_traceback`(excid=None)

    render one or all of my tracebacks to a list of lines

## 3 Functions

`IPython.parallel.error.``collect_exceptions`(rdict_or_list, method='unspecified')

  check a result dict for errors, and raise CompositeError if any exist. Passthrough otherwise.

`IPython.parallel.error.``wrap_exception`(engine_info={})

`IPython.parallel.error.``unwrap_exception`(content)