Selector

class sisl.Selector(routines=None, ordered=False)

Bases: object

Base class for implementing a selector of class routines

This class should contain a list of routines and may then be used to always return the best performant routine. The performance of a method is based on a pre-selected metric (time, memory, etc.).

The chosen method will be based on the routine which has the highest metric. E.g. for time the metric could be \(1/(stop - start)\).

This is done on a per-class basis where this class should initially determine which routine is the best performing one and then always return that one.

routines

this is a list of functions that will be selected from.

Type

list of func

ordered

If False a simple selection of the most performant one will be chosen. If True, it will check the routines in order and once one of the routines is less performant it will choose from the setof currently runned routines.

Type

bool

Attributes

__doc__
__module__
__slots__
_best
_metric
_ordered
_routines
best
metric
ordered
routines

Methods

__call__(*args, **kwargs)	Call the function that optimizes the run-time the most
__delattr__	Implement delattr(self, name).
__dir__	Default dir() implementation.
__eq__	Return self==value.
__format__	Default object formatter.
__ge__	Return self>=value.
__getattribute__	Return getattr(self, name).
__gt__	Return self>value.
__hash__	Return hash(self).
__init__([routines, ordered])	Initialize self.
__init_subclass__	This method is called when a class is subclassed.
__le__	Return self<=value.
__len__()	Number of routines that it can select from
__lt__	Return self<value.
__ne__	Return self!=value.
__new__	Create and return a new object.
__reduce__	Helper for pickle.
__reduce_ex__	Helper for pickle.
__repr__	Return repr(self).
__setattr__	Implement setattr(self, name, value).
__sizeof__	Size of object in memory, in bytes.
__str__()	A representation of the current selector state
__subclasshook__	Abstract classes can override this to customize issubclass().
append(routine)	Prepends a new routine to the selector
next()	Choose the next routine that requires metric analysis
prepend(routine)	Prepends a new routine to the selector
reset()	Reset the metric table to redo the performance checks
select_best([routine])	Update the best routine, if applicable
start()	Start the metric profiler
stop(start)	Stop the metric profiler

append(routine)

Prepends a new routine to the selector

Parameters

routine (func) – the new routine to be tested in the selector

property best

property metric

next()

Choose the next routine that requires metric analysis

Returns

• int – routine index

• callable – func is the routine that is to be runned next (or if index is negative, then it refers to the most optimal routine

property ordered

prepend(routine)

Prepends a new routine to the selector

Parameters

routine (func) – the new routine to be tested in the selector

reset()

Reset the metric table to redo the performance checks

property routines

select_best(routine=None)

Update the best routine, if applicable

Update the selector to choose the best method. If not all routines have been carried through, then no best routine will be selected (unless self.ordered is True).

By passing a routine as an argument that given routine will by default be the chosen best algorithm.

Parameters

routine (func or str) –

If None is passed (the default) it will select the best default routine based on the stored metrics. If, however, not all metric values has been created no routine will be selected.

If passing a func that function will be chosen as the best method

start()

Start the metric profiler

This routine should return an initial state value. The difference between stop() - start() should yield a metric identifier which may be used to control the used algorithm.

The best method A large metric identifier results in the use of the routine.

stop(start)

Stop the metric profiler

This routine returns the actual metric for the method. Its input is what start returns and it may be of any value.

A large metric identifier results in the use of the routine.

Parameters

start (obj) – the output of the start() routine to convert to actual metric identifier