class invoke.executor.Executor(collection, config=None, core=None)

An execution strategy for Task objects.

Subclasses may override various extension points to change, add or remove behavior.

__init__(collection, config=None, core=None)

Initialize executor with handles to necessary data structures.

  • collection – A Collection used to look up requested tasks (and their default config data, if any) by name during execution.
  • config – An optional Config holding configuration state. Defaults to an empty Config if not given.
  • core

    An optional ParserContext holding core program arguments. Defaults to None.


    This is unused by the default implementation, but may be useful to subclasses which care about specific core arguments re: execution strategy, use of the parse remainder, etc.


list of weak references to the object (if defined)


Deduplicate a list of tasks.

Parameters:calls – An iterable of Call objects representing tasks.
Returns:A list of Call objects.

Execute one or more tasks in sequence.


An all-purpose iterable of “tasks to execute”, each member of which may take one of the following forms:

A string naming a task from the Executor’s Collection. This name may contain dotted syntax appropriate for calling namespaced tasks, e.g. subcollection.taskname. Such tasks are executed without arguments.

A two-tuple whose first element is a task name string (as above) and whose second element is a dict suitable for use as **kwargs when calling the named task. E.g.:

    ('task1', {}),
    ('task2', {'arg1': 'val1'}),

is equivalent, roughly, to:


A `.ParserContext` instance, whose .name attribute is used as the task name and whose .as_kwargs attribute is used as the task kwargs (again following the above specifications).


When called without any arguments at all (i.e. when *tasks is empty), the default task from self.collection is used instead, if defined.

Returns:A dict mapping task objects to their return values.

This dict may include pre- and post-tasks if any were executed. For example, in a collection with a build task depending on another task named setup, executing build will result in a dict with two keys, one for build and one for setup.


Expand a list of Call objects into a near-final list of same.

The default implementation of this method simply adds a task’s pre/post-task list before/after the task itself, as necessary.

Subclasses may wish to do other things in addition (or instead of) the above, such as multiplying the calls by argument vectors or similar.


Transform arbitrary task list w/ various types, into Call objects.

See docstring for execute for details.