aiida.engine.processes package

Module for processes and related utilities.

class aiida.engine.processes.ProcessBuilder(process_class)

Bases: aiida.engine.processes.builder.ProcessBuilderNamespace

A process builder that helps setting up the inputs for creating a new process.

__abstractmethods__ = frozenset({})

__init__(process_class)

Construct a ProcessBuilder instance for the given Process class.

Parameters

process_class – the Process subclass

__module__ = 'aiida.engine.processes.builder'

_abc_impl = <_abc_data object>

property process_class

class aiida.engine.processes.ProcessBuilderNamespace(port_namespace)

Bases: collections.abc.MutableMapping

Input namespace for the ProcessBuilder.

Dynamically generates the getters and setters for the input ports of a given PortNamespace

__abstractmethods__ = frozenset({})

__delitem__(item)

__dict__ = mappingproxy({'__module__': 'aiida.engine.processes.builder', '__doc__': 'Input namespace for the `ProcessBuilder`.\n\n Dynamically generates the getters and setters for the input ports of a given PortNamespace\n ', '__init__': <function ProcessBuilderNamespace.__init__>, '__setattr__': <function ProcessBuilderNamespace.__setattr__>, '__repr__': <function ProcessBuilderNamespace.__repr__>, '__dir__': <function ProcessBuilderNamespace.__dir__>, '__iter__': <function ProcessBuilderNamespace.__iter__>, '__len__': <function ProcessBuilderNamespace.__len__>, '__getitem__': <function ProcessBuilderNamespace.__getitem__>, '__setitem__': <function ProcessBuilderNamespace.__setitem__>, '__delitem__': <function ProcessBuilderNamespace.__delitem__>, '_update': <function ProcessBuilderNamespace._update>, '_inputs': <function ProcessBuilderNamespace._inputs>, '_prune': <function ProcessBuilderNamespace._prune>, '__dict__': <attribute '__dict__' of 'ProcessBuilderNamespace' objects>, '__weakref__': <attribute '__weakref__' of 'ProcessBuilderNamespace' objects>, '__abstractmethods__': frozenset(), '_abc_impl': <_abc_data object>})

__dir__()

Default dir() implementation.

__getitem__(item)

__init__(port_namespace)

Dynamically construct the get and set properties for the ports of the given port namespace.

For each port in the given port namespace a get and set property will be constructed dynamically and added to the ProcessBuilderNamespace. The docstring for these properties will be defined by calling str() on the Port, which should return the description of the Port.

Parameters

port_namespace (str) – the inputs PortNamespace for which to construct the builder

__iter__()

__len__()

__module__ = 'aiida.engine.processes.builder'

__repr__()

Return repr(self).

__setattr__(attr, value)

Assign the given value to the port with key attr.

Note

Any attributes without a leading underscore being set correspond to inputs and should hence be validated with respect to the corresponding input port from the process spec

Parameters

• attr (str) – attribute

• value – value

__setitem__(item, value)

__weakref__

list of weak references to the object (if defined)

_abc_impl = <_abc_data object>

_inputs(prune=False)

Return the entire mapping of inputs specified for this builder.

Parameters

prune – boolean, when True, will prune nested namespaces that contain no actual values whatsoever

Returns

mapping of inputs ports and their input values.

_prune(value)

Prune a nested mapping from all mappings that are completely empty.

Note

a nested mapping that is completely empty means it contains at most other empty mappings. Other null values, such as None or empty lists, should not be pruned.

Parameters

value – a nested mapping of port values

Returns

the same mapping but without any nested namespace that is completely empty.

_update(*args, **kwds)

Update the values of the builder namespace passing a mapping as argument or individual keyword value pairs.

The method is prefixed with an underscore in order to not reserve the name for a potential port, but in principle the method functions just as collections.MutableMapping.update.

Parameters

• args (list) – a single mapping that should be mapped on the namespace

• kwds (dict) – keyword value pairs that should be mapped onto the ports

class aiida.engine.processes.CalcJob(*args, **kwargs)

Bases: aiida.engine.processes.process.Process

Implementation of the CalcJob process.

_Process__called = True

__abstractmethods__ = frozenset({})

__init__(*args, **kwargs)

Construct a CalcJob instance.

Construct the instance only if it is a sub class of CalcJob, otherwise raise InvalidOperation.

See documentation of aiida.engine.Process.

__module__ = 'aiida.engine.processes.calcjobs.calcjob'

_abc_impl = <_abc_data object>

_node_class

alias of aiida.orm.nodes.process.calculation.calcjob.CalcJobNode

_spec = <aiida.engine.processes.process_spec.CalcJobProcessSpec object>

_spec_class

alias of aiida.engine.processes.process_spec.CalcJobProcessSpec

classmethod define(spec)

classmethod get_state_classes()

link_label_retrieved = 'retrieved'

on_terminated()

Cleanup the node by deleting the calulation job state.

Note

This has to be done before calling the super because that will seal the node after we cannot change it

property options

Return the options of the metadata that were specified when this process instance was launched.

Returns

options dictionary

Return type

dict

parse(retrieved_temporary_folder=None)

Parse a retrieved job calculation.

This is called once it’s finished waiting for the calculation to be finished and the data has been retrieved.

prepare_for_submission(folder)

Prepare files for submission of calculation.

presubmit(folder)

Prepares the calculation folder with all inputs, ready to be copied to the cluster.

Parameters

folder (aiida.common.folders.Folder) – a SandboxFolder that can be used to write calculation input files and the scheduling script.

Return calcinfo

the CalcInfo object containing the information needed by the daemon to handle operations.

Rtype calcinfo

aiida.common.CalcInfo

run()

Run the calculation job.

This means invoking the presubmit and storing the temporary folder in the node’s repository. Then we move the process in the Wait state, waiting for the UPLOAD transport task to be started.

spec_options = <aiida.engine.processes.ports.PortNamespace object>

class aiida.engine.processes.ExitCode(status, message)

Bases: tuple

__getnewargs__()

Return self as a plain tuple. Used by copy and pickle.

__module__ = 'aiida.engine.processes.exit_code'

static __new__(_cls, status=0, message=None)

Create new instance of ExitCode(status, message)

__repr__()

Return a nicely formatted representation string

__slots__ = ()

_asdict()

Return a new OrderedDict which maps field names to their values.

_fields = ('status', 'message')

_fields_defaults = {}

classmethod _make(iterable)

Make a new ExitCode object from a sequence or iterable

_replace(**kwds)

Return a new ExitCode object replacing specified fields with new values

property message

Alias for field number 1

property status

Alias for field number 0

class aiida.engine.processes.ExitCodesNamespace(dictionary=None)

Bases: aiida.common.extendeddicts.AttributeDict

A namespace of ExitCode tuples that can be accessed through getattr as well as getitem. Additionally, the collection can be called with an identifier, that can either reference the integer status of the ExitCode that needs to be retrieved or the key in the collection

__call__(identifier)

Return a specific exit code identified by either its exit status or label

Parameters

identifier (str) – the identifier of the exit code. If the type is integer, it will be interpreted as the exit code status, otherwise it be interpreted as the exit code label

Returns

an ExitCode named tuple

Return type

aiida.engine.ExitCode

Raises

ValueError – if no exit code with the given label is defined for this process

__module__ = 'aiida.engine.processes.exit_code'

aiida.engine.processes.calcfunction(function)

A decorator to turn a standard python function into a calcfunction. Example usage:

>>> from aiida.orm import Int
>>>
>>> # Define the calcfunction
>>> @calcfunction
>>> def sum(a, b):
>>>    return a + b
>>> # Run it with some input
>>> r = sum(Int(4), Int(5))
>>> print(r)
9
>>> r.get_incoming().all() 
[Neighbor(link_type='', link_label='result',
node=<CalcFunctionNode: uuid: ce0c63b3-1c84-4bb8-ba64-7b70a36adf34 (pk: 3567)>)]
>>> r.get_incoming().get_node_by_label('result').get_incoming().all_nodes()
[4, 5]

Parameters

function (callable) – The function to decorate.

Returns

The decorated function.

Return type

callable

aiida.engine.processes.workfunction(function)

A decorator to turn a standard python function into a workfunction. Example usage:

>>> from aiida.orm import Int
>>>
>>> # Define the workfunction
>>> @workfunction
>>> def select(a, b):
>>>    return a
>>> # Run it with some input
>>> r = select(Int(4), Int(5))
>>> print(r)
4
>>> r.get_incoming().all() 
[Neighbor(link_type='', link_label='result',
node=<WorkFunctionNode: uuid: ce0c63b3-1c84-4bb8-ba64-7b70a36adf34 (pk: 3567)>)]
>>> r.get_incoming().get_node_by_label('result').get_incoming().all_nodes()
[4, 5]

Parameters

function (callable) – The function to decorate.

Returns

The decorated function.

Return type

callable

class aiida.engine.processes.FunctionProcess(*args, **kwargs)

Bases: aiida.engine.processes.process.Process

Function process class used for turning functions into a Process

_Process__called = True

__abstractmethods__ = frozenset({})

__init__(*args, **kwargs)

Process constructor.

Parameters

• inputs (dict) – process inputs

• logger (logging.Logger) – aiida logger

• runner – process runner

• parent_pid (int) – id of parent process

• enable_persistence (bool) – whether to persist this process

Type

aiida.engine.runners.Runner

__module__ = 'aiida.engine.processes.functions'

_abc_impl = <_abc_data object>

static _func(*_args, **_kwargs)

This is used internally to store the actual function that is being wrapped and will be replaced by the build method.

_func_args = None

_setup_db_record()

Set up the database record for the process.

_spec = <aiida.engine.processes.process_spec.ProcessSpec object>

classmethod args_to_dict(*args)

Create an input dictionary (of form label -> value) from supplied args.

Parameters

args (list) – The values to use for the dictionary

Returns

A label -> value dictionary

Return type

dict

static build(func, node_class)

Build a Process from the given function.

All function arguments will be assigned as process inputs. If keyword arguments are specified then these will also become inputs.

Parameters

• func (callable) – The function to build a process from

• node_class (aiida.orm.nodes.process.process.ProcessNode) – Provide a custom node class to be used, has to be constructable with no arguments. It has to be a sub class of ProcessNode and the mixin FunctionCalculationMixin.

Returns

A Process class that represents the function

Return type

FunctionProcess

classmethod create_inputs(*args, **kwargs)

Create the input args for the FunctionProcess.

Return type

dict

execute()

Execute the process.

classmethod get_or_create_db_record()

Create a process node that represents what happened in this process.

Returns

A process node

Return type

aiida.orm.ProcessNode

property process_class

Return the class that represents this Process, for the FunctionProcess this is the function itself.

For a standard Process or sub class of Process, this is the class itself. However, for legacy reasons, the Process class is a wrapper around another class. This function returns that original class, i.e. the class that really represents what was being executed.

Returns

A Process class that represents the function

Return type

FunctionProcess

run()

Run the process.

Return type

aiida.engine.ExitCode

classmethod validate_inputs(*args, **kwargs)

Validate the positional and keyword arguments passed in the function call.

Raises

TypeError – if more positional arguments are passed than the function defines

class aiida.engine.processes.PortNamespace(*args, **kwargs)

Bases: aiida.engine.processes.ports.WithNonDb, plumpy.ports.PortNamespace

Sub class of plumpy.PortNamespace which implements the serialize method to support automatic recursive serialization of a given mapping onto the ports of the PortNamespace.

__abstractmethods__ = frozenset({})

__module__ = 'aiida.engine.processes.ports'

__setitem__(key, port)

Ensure that a Port being added inherits the non_db attribute if not explicitly defined at construction.

The reasoning is that if a PortNamespace has non_db=True, which is different from the default value, very often all leaves should be also non_db=True. To prevent a user from having to specify it manually everytime we overload the value here, unless it was specifically set during construction.

Note that the non_db attribute is not present for all Port sub classes so we have to check for it first.

__slotnames__ = []

_abc_impl = <_abc_data object>

serialize(mapping, breadcrumbs=())

Serialize the given mapping onto this Portnamespace.

It will recursively call this function on any nested PortNamespace or the serialize function on any Ports.

Parameters

• mapping – a mapping of values to be serialized

• breadcrumbs – a tuple with the namespaces of parent namespaces

Returns

the serialized mapping

static validate_port_name(port_name)

Validate the given port name.

Valid port names adhere to the following restrictions:

• Is a valid link label (see below)

• Does not contain two or more consecutive underscores

Valid link labels adhere to the following restrictions:

• Has to be a valid python identifier

• Can only contain alphanumeric characters and underscores

• Can not start or end with an underscore

Parameters

port_name – the proposed name of the port to be added

Raises

• TypeError – if the port name is not a string type

• ValueError – if the port name is invalid

class aiida.engine.processes.InputPort(*args, **kwargs)

Bases: aiida.engine.processes.ports.WithSerialize, aiida.engine.processes.ports.WithNonDb, plumpy.ports.InputPort

Sub class of plumpy.InputPort which mixes in the WithSerialize and WithNonDb mixins to support automatic value serialization to database storable types and support non database storable input types as well.

__abstractmethods__ = frozenset({})

__module__ = 'aiida.engine.processes.ports'

__slotnames__ = []

_abc_impl = <_abc_data object>

get_description()

Return a description of the InputPort, which will be a dictionary of its attributes

Returns

a dictionary of the stringified InputPort attributes

class aiida.engine.processes.OutputPort(name, valid_type=None, help=None, required=True, validator=None)

Bases: plumpy.ports.Port

__abstractmethods__ = frozenset({})

__module__ = 'plumpy.ports'

__slotnames__ = []

_abc_impl = <_abc_data object>

class aiida.engine.processes.CalcJobOutputPort(*args, **kwargs)

Bases: plumpy.ports.OutputPort

Sub class of plumpy.OutputPort which adds the _pass_to_parser attribute.

__abstractmethods__ = frozenset({})

__init__(*args, **kwargs)

Initialize self. See help(type(self)) for accurate signature.

__module__ = 'aiida.engine.processes.ports'

_abc_impl = <_abc_data object>

property pass_to_parser

class aiida.engine.processes.WithNonDb(*args, **kwargs)

Bases: object

A mixin that adds support to a port to flag a that should not be stored in the database using the non_db=True flag.

The mixins have to go before the main port class in the superclass order to make sure the mixin has the chance to strip out the non_db keyword.

__dict__ = mappingproxy({'__module__': 'aiida.engine.processes.ports', '__doc__': '\n A mixin that adds support to a port to flag a that should not be stored\n in the database using the non_db=True flag.\n\n The mixins have to go before the main port class in the superclass order\n to make sure the mixin has the chance to strip out the non_db keyword.\n ', '__init__': <function WithNonDb.__init__>, 'non_db_explicitly_set': <property object>, 'non_db': <property object>, '__dict__': <attribute '__dict__' of 'WithNonDb' objects>, '__weakref__': <attribute '__weakref__' of 'WithNonDb' objects>})

__init__(*args, **kwargs)

Initialize self. See help(type(self)) for accurate signature.

__module__ = 'aiida.engine.processes.ports'

__weakref__

list of weak references to the object (if defined)

property non_db

Return whether the value of this Port should be stored as a Node in the database.

Returns

boolean, True if it should be storable as a Node, False otherwise

property non_db_explicitly_set

Return whether the a value for non_db was explicitly passed in the construction of the Port.

Returns

boolean, True if non_db was explicitly defined during construction, False otherwise

class aiida.engine.processes.WithSerialize(*args, **kwargs)

Bases: object

A mixin that adds support for a serialization function which is automatically applied on inputs that are not AiiDA data types.

__dict__ = mappingproxy({'__module__': 'aiida.engine.processes.ports', '__doc__': '\n A mixin that adds support for a serialization function which is automatically applied on inputs\n that are not AiiDA data types.\n ', '__init__': <function WithSerialize.__init__>, 'serialize': <function WithSerialize.serialize>, '__dict__': <attribute '__dict__' of 'WithSerialize' objects>, '__weakref__': <attribute '__weakref__' of 'WithSerialize' objects>})

__init__(*args, **kwargs)

Initialize self. See help(type(self)) for accurate signature.

__module__ = 'aiida.engine.processes.ports'

__weakref__

list of weak references to the object (if defined)

serialize(value)

Serialize the given value if it is not already a Data type and a serializer function is defined

Parameters

value – the value to be serialized

Returns

a serialized version of the value or the unchanged value

class aiida.engine.processes.Process(inputs=None, logger=None, runner=None, parent_pid=None, enable_persistence=True)

Bases: plumpy.processes.Process

This class represents an AiiDA process which can be executed and will have full provenance saved in the database.

SINGLE_OUTPUT_LINKNAME = 'result'

class SaveKeys

Bases: enum.Enum

Keys used to identify things in the saved instance state bundle.

CALC_ID = 'calc_id'

__module__ = 'aiida.engine.processes.process'

_Process__called = True

__abstractmethods__ = frozenset({})

__init__(inputs=None, logger=None, runner=None, parent_pid=None, enable_persistence=True)

Process constructor.

Parameters

• inputs (dict) – process inputs

• logger (logging.Logger) – aiida logger

• runner – process runner

• parent_pid (int) – id of parent process

• enable_persistence (bool) – whether to persist this process

Type

aiida.engine.runners.Runner

__module__ = 'aiida.engine.processes.process'

_abc_impl = <_abc_data object>

_auto_persist = {'_CREATION_TIME', '_enable_persistence', '_future', '_parent_pid', '_paused', '_pid', '_pre_paused_status', '_status'}

_create_and_setup_db_record()

Create and setup the database record for this process

Returns

the uuid of the process

Return type

uuid.UUID

_flat_inputs()

Return a flattened version of the parsed inputs dictionary.

The eventual keys will be a concatenation of the nested keys. Note that the metadata dictionary, if present, is not passed, as those are dealt with separately in _setup_metadata.

Returns

flat dictionary of parsed inputs

Return type

dict

_flat_outputs()

Return a flattened version of the registered outputs dictionary.

The eventual keys will be a concatenation of the nested keys.

Returns

flat dictionary of parsed outputs

_flatten_inputs(port, port_value, parent_name='', separator='__')

Function that will recursively flatten the inputs dictionary, omitting inputs for ports that are marked as being non database storable

Parameters

• port (plumpy.ports.Port) – port against which to map the port value, can be InputPort or PortNamespace

• port_value – value for the current port, can be a Mapping

• parent_name (str) – the parent key with which to prefix the keys

• separator (str) – character to use for the concatenation of keys

Returns

flat list of inputs

Return type

list

_flatten_outputs(port, port_value, parent_name='', separator='__')

Function that will recursively flatten the outputs dictionary.

Parameters

• port (plumpy.ports.Port) – port against which to map the port value, can be OutputPort or PortNamespace

• port_value – value for the current port, can be a Mapping

• parent_name (str) – the parent key with which to prefix the keys

• separator (str) – character to use for the concatenation of keys

Returns

flat list of outputs

Return type

list

static _get_namespace_list(namespace=None, agglomerate=True)

Get the list of namespaces in a given namespace.

Parameters

• namespace (str) – name space

• agglomerate (bool) – If set to true, all parent namespaces of the given namespace will also be searched.

Returns

namespace list

Return type

list

_node_class

alias of aiida.orm.nodes.process.process.ProcessNode

_save_checkpoint()

Save the current state in a chechpoint if persistence is enabled and the process state is not terminal

If the persistence call excepts with a PersistenceError, it will be caught and a warning will be logged.

_setup_db_record()

Create the database record for this process and the links with respect to its inputs

This function will set various attributes on the node that serve as a proxy for attributes of the Process. This is essential as otherwise this information could only be introspected through the Process itself, which is only available to the interpreter that has it in memory. To make this data introspectable from any interpreter, for example for the command line interface, certain Process attributes are proxied through the calculation node.

In addition, the parent calculation will be setup with a CALL link if applicable and all inputs will be linked up as well.

_setup_inputs()

Create the links between the input nodes and the ProcessNode that represents this process.

_setup_metadata()

Store the metadata on the ProcessNode.

_spec = <aiida.engine.processes.process_spec.ProcessSpec object>

_spec_class

alias of aiida.engine.processes.process_spec.ProcessSpec

classmethod build_process_type()

The process type.

Returns

string of the process type

Return type

str

Note: This could be made into a property ‘process_type’ but in order to have it be a property of the class it would need to be defined in the metaclass, see https://bugs.python.org/issue20659

decode_input_args(encoded)

Decode saved input arguments as they came from the saved instance state Bundle

Parameters

encoded – encoded (serialized) inputs

Returns

The decoded input args

classmethod define(spec)

encode_input_args(inputs)

Encode input arguments such that they may be saved in a Bundle

Parameters

inputs – A mapping of the inputs as passed to the process

Returns

The encoded (serialized) inputs

exit_codes = {'ERROR_INVALID_OUTPUT': ExitCode(status=10, message='The process returned an invalid output.'), 'ERROR_LEGACY_FAILURE': ExitCode(status=2, message='The process failed with legacy failure mode.'), 'ERROR_MISSING_OUTPUT': ExitCode(status=11, message='The process did not register a required output.'), 'ERROR_UNSPECIFIED': ExitCode(status=1, message='The process has failed with an unspecified error.')}

exposed_inputs(process_class, namespace=None, agglomerate=True)

Gather a dictionary of the inputs that were exposed for a given Process class under an optional namespace.

Parameters

• process_class (aiida.engine.Process) – Process class whose inputs to try and retrieve

• namespace (str) – PortNamespace in which to look for the inputs

• agglomerate (bool) – If set to true, all parent namespaces of the given namespace will also be searched for inputs. Inputs in lower-lying namespaces take precedence.

Returns

exposed inputs

Return type

dict

exposed_outputs(node, process_class, namespace=None, agglomerate=True)

Return the outputs which were exposed from the process_class and emitted by the specific node

Parameters

• node (aiida.orm.nodes.process.ProcessNode) – process node whose outputs to try and retrieve

• namespace (str) – Namespace in which to search for exposed outputs.

• agglomerate (bool) – If set to true, all parent namespaces of the given namespace will also be searched for outputs. Outputs in lower-lying namespaces take precedence.

Returns

exposed outputs

Return type

dict

classmethod get_builder()

classmethod get_exit_statuses(exit_code_labels)

Return the exit status (integers) for the given exit code labels.

Parameters

exit_code_labels – a list of strings that reference exit code labels of this process class

Returns

list of exit status integers that correspond to the given exit code labels

Raises

AttributeError – if at least one of the labels does not correspond to an existing exit code

classmethod get_or_create_db_record()

Create a process node that represents what happened in this process.

Returns

A process node

Return type

aiida.orm.ProcessNode

get_parent_calc()

Get the parent process node

Returns

the parent process node if there is one

Return type

aiida.orm.ProcessNode

get_provenance_inputs_iterator()

Get provenance input iterator.

Return type

filter

init()

kill(msg=None)

Kill the process and all the children calculations it called

Parameters

msg (str) – message

Return type

bool

load_instance_state(saved_state, load_context)

Load instance state.

Parameters

• saved_state – saved instance state

• load_context (plumpy.persistence.LoadSaveContext) –

property metadata

Return the metadata that were specified when this process instance was launched.

Returns

metadata dictionary

Return type

dict

property node

Return the ProcessNode used by this process to represent itself in the database.

Returns

instance of sub class of ProcessNode

Return type

aiida.orm.ProcessNode

on_create()

Called when a Process is created.

on_entered(from_state)

on_entering(state)

on_except(exc_info)

Log the exception by calling the report method with formatted stack trace from exception info object and store the exception string as a node attribute

Parameters

exc_info – the sys.exc_info() object (type, value, traceback)

on_finish(result, successful)

Set the finish status on the process node.

Parameters

• result (int or aiida.engine.ExitCode) – result of the process

• successful (bool) – whether execution was successful

on_output_emitting(output_port, value)

The process has emitted a value on the given output port.

Parameters

• output_port (str) – The output port name the value was emitted on

• value – The value emitted

on_paused(msg=None)

The Process was paused so set the paused attribute on the process node

Parameters

msg (str) – message

on_playing()

The Process was unpaused so remove the paused attribute on the process node

on_terminated()

Called when a Process enters a terminal state.

out(output_port, value=None)

Attach output to output port.

The name of the port will be used as the link label.

Parameters

• output_port (str) – name of output port

• value – value to put inside output port

out_many(out_dict)

Attach outputs to multiple output ports.

Keys of the dictionary will be used as output port names, values as outputs.

Parameters

out_dict (dict) – output dictionary

report(msg, *args, **kwargs)

Log a message to the logger, which should get saved to the database through the attached DbLogHandler.

The pk, class name and function name of the caller are prepended to the given message

Parameters

• msg (str) – message to log

• args (list) – args to pass to the log call

• kwargs (dict) – kwargs to pass to the log call

property runner

Get process runner.

Return type

aiida.engine.runners.Runner

save_instance_state(out_state, save_context)

Save instance state.

See documentation of plumpy.processes.Process.save_instance_state().

set_status(status)

The status of the Process is about to be changed, so we reflect this is in node’s attribute proxy.

Parameters

status (str) – the status message

spec_metadata = <aiida.engine.processes.ports.PortNamespace object>

submit(process, *args, **kwargs)

Submit process for execution.

Parameters

process (aiida.engine.Process) – process

update_node_state(state)

update_outputs()

Attach new outputs to the node since the last call.

Does nothing, if self.metadata.store_provenance is False.

property uuid

Return the UUID of the process which corresponds to the UUID of its associated ProcessNode.

Returns

the UUID associated to this process instance

class aiida.engine.processes.ProcessState

Bases: enum.Enum

The possible states that a Process can be in.

CREATED = 'created'

EXCEPTED = 'excepted'

FINISHED = 'finished'

KILLED = 'killed'

RUNNING = 'running'

WAITING = 'waiting'

__module__ = 'plumpy.process_states'

aiida.engine.processes.ToContext

alias of builtins.dict

aiida.engine.processes.assign_(target)

Convenience function that will construct an Awaitable for a given class instance with the context action set to ASSIGN. When the awaitable target is completed it will be assigned to the context for a key that is to be defined later

Parameters

target – an instance of a Process or Awaitable

Returns

the awaitable

Return type

Awaitable

aiida.engine.processes.append_(target)

Convenience function that will construct an Awaitable for a given class instance with the context action set to APPEND. When the awaitable target is completed it will be appended to a list in the context for a key that is to be defined later

Parameters

target – an instance of a Process or Awaitable

Returns

the awaitable

Return type

Awaitable

class aiida.engine.processes.WorkChain(inputs=None, logger=None, runner=None, enable_persistence=True)

Bases: aiida.engine.processes.process.Process

The WorkChain class is the principle component to implement workflows in AiiDA.

_CONTEXT = 'CONTEXT'

_Process__called = True

_STEPPER_STATE = 'stepper_state'

__abstractmethods__ = frozenset({})

__init__(inputs=None, logger=None, runner=None, enable_persistence=True)

Construct a WorkChain instance.

Construct the instance only if it is a sub class of WorkChain, otherwise raise InvalidOperation.

Parameters

• inputs (dict) – work chain inputs

• logger (logging.Logger) – aiida logger

• runner – work chain runner

• enable_persistence (bool) – whether to persist this work chain

Type

aiida.engine.runners.Runner

__module__ = 'aiida.engine.processes.workchains.workchain'

_abc_impl = <_abc_data object>

_auto_persist = {'_CREATION_TIME', '_awaitables', '_enable_persistence', '_future', '_parent_pid', '_paused', '_pid', '_pre_paused_status', '_status'}

_do_step()

Execute the next step in the outline and return the result.

If the stepper returns a non-finished status and the return value is of type ToContext, the contents of the ToContext container will be turned into awaitables if necessary. If any awaitables were created, the process will enter in the Wait state, otherwise it will go to Continue. When the stepper returns that it is done, the stepper result will be converted to None and returned, unless it is an integer or instance of ExitCode.

_node_class

alias of aiida.orm.nodes.process.workflow.workchain.WorkChainNode

_spec = <aiida.engine.processes.workchains.workchain.WorkChainSpec object>

_spec_class

alias of WorkChainSpec

_store_nodes(data)

Recurse through a data structure and store any unstored nodes that are found along the way

Parameters

data – a data structure potentially containing unstored nodes

_update_process_status()

Set the process status with a message accounting the current sub processes that we are waiting for.

action_awaitables()

Handle the awaitables that are currently registered with the work chain

Depending on the class type of the awaitable’s target a different callback function will be bound with the awaitable and the runner will be asked to call it when the target is completed

property ctx

Get context.

Return type

aiida.common.extendeddicts.AttributeDict

insert_awaitable(awaitable)

Insert an awaitable that should be terminated before before continuing to the next step.

Parameters

awaitable (aiida.engine.processes.workchains.awaitable.Awaitable) – the thing to await

load_instance_state(saved_state, load_context)

Load instance state.

Parameters

• saved_state – saved instance state

• load_context (plumpy.persistence.LoadSaveContext) –

on_exiting()

Ensure that any unstored nodes in the context are stored, before the state is exited

After the state is exited the next state will be entered and if persistence is enabled, a checkpoint will be saved. If the context contains unstored nodes, the serialization necessary for checkpointing will fail.

on_process_finished(awaitable, pk)

Callback function called by the runner when the process instance identified by pk is completed.

The awaitable will be effectuated on the context of the work chain and removed from the internal list. If all awaitables have been dealt with, the work chain process is resumed.

Parameters

• awaitable – an Awaitable instance

• pk (int) – the pk of the awaitable’s target

on_run()

on_wait(awaitables)

remove_awaitable(awaitable)

Remove an awaitable.

Precondition: must be an awaitable that was previously inserted.

Parameters

awaitable – the awaitable to remove

run()

save_instance_state(out_state, save_context)

Save instance stace.

Parameters

• out_state – state to save in

• save_context (plumpy.persistence.LoadSaveContext) –

to_context(**kwargs)

Add a dictionary of awaitables to the context.

This is a convenience method that provides syntactic sugar, for a user to add multiple intersteps that will assign a certain value to the corresponding key in the context of the work chain.

aiida.engine.processes.if_(condition)

A conditional that can be used in a workchain outline.

Use as:

if_(cls.conditional)(
  cls.step1,
  cls.step2
)

Each step can, of course, also be any valid workchain step e.g. conditional.

Parameters

condition – The workchain method that will return True or False

aiida.engine.processes.while_(condition)

A while loop that can be used in a workchain outline.

Use as:

while_(cls.conditional)(
  cls.step1,
  cls.step2
)

Each step can, of course, also be any valid workchain step e.g. conditional.

Parameters

condition – The workchain method that will return True or False

Subpackages

• aiida.engine.processes.calcjobs package
  • Submodules
• aiida.engine.processes.workchains package
  • Submodules

Submodules

Convenience classes to help building the input dictionaries for Processes.

class aiida.engine.processes.builder.ProcessBuilder(process_class)

Bases: aiida.engine.processes.builder.ProcessBuilderNamespace

A process builder that helps setting up the inputs for creating a new process.

__abstractmethods__ = frozenset({})

__init__(process_class)

Construct a ProcessBuilder instance for the given Process class.

Parameters

process_class – the Process subclass

__module__ = 'aiida.engine.processes.builder'

_abc_impl = <_abc_data object>

property process_class

class aiida.engine.processes.builder.ProcessBuilderNamespace(port_namespace)

Bases: collections.abc.MutableMapping

Input namespace for the ProcessBuilder.

Dynamically generates the getters and setters for the input ports of a given PortNamespace

__abstractmethods__ = frozenset({})

__delitem__(item)

__dict__ = mappingproxy({'__module__': 'aiida.engine.processes.builder', '__doc__': 'Input namespace for the `ProcessBuilder`.\n\n Dynamically generates the getters and setters for the input ports of a given PortNamespace\n ', '__init__': <function ProcessBuilderNamespace.__init__>, '__setattr__': <function ProcessBuilderNamespace.__setattr__>, '__repr__': <function ProcessBuilderNamespace.__repr__>, '__dir__': <function ProcessBuilderNamespace.__dir__>, '__iter__': <function ProcessBuilderNamespace.__iter__>, '__len__': <function ProcessBuilderNamespace.__len__>, '__getitem__': <function ProcessBuilderNamespace.__getitem__>, '__setitem__': <function ProcessBuilderNamespace.__setitem__>, '__delitem__': <function ProcessBuilderNamespace.__delitem__>, '_update': <function ProcessBuilderNamespace._update>, '_inputs': <function ProcessBuilderNamespace._inputs>, '_prune': <function ProcessBuilderNamespace._prune>, '__dict__': <attribute '__dict__' of 'ProcessBuilderNamespace' objects>, '__weakref__': <attribute '__weakref__' of 'ProcessBuilderNamespace' objects>, '__abstractmethods__': frozenset(), '_abc_impl': <_abc_data object>})

__dir__()

Default dir() implementation.

__getitem__(item)

__init__(port_namespace)

Dynamically construct the get and set properties for the ports of the given port namespace.

For each port in the given port namespace a get and set property will be constructed dynamically and added to the ProcessBuilderNamespace. The docstring for these properties will be defined by calling str() on the Port, which should return the description of the Port.

Parameters

port_namespace (str) – the inputs PortNamespace for which to construct the builder

__iter__()

__len__()

__module__ = 'aiida.engine.processes.builder'

__repr__()

Return repr(self).

__setattr__(attr, value)

Assign the given value to the port with key attr.

Note

Any attributes without a leading underscore being set correspond to inputs and should hence be validated with respect to the corresponding input port from the process spec

Parameters

• attr (str) – attribute

• value – value

__setitem__(item, value)

__weakref__

list of weak references to the object (if defined)

_abc_impl = <_abc_data object>

_inputs(prune=False)

Return the entire mapping of inputs specified for this builder.

Parameters

prune – boolean, when True, will prune nested namespaces that contain no actual values whatsoever

Returns

mapping of inputs ports and their input values.

_prune(value)

Prune a nested mapping from all mappings that are completely empty.

Note

a nested mapping that is completely empty means it contains at most other empty mappings. Other null values, such as None or empty lists, should not be pruned.

Parameters

value – a nested mapping of port values

Returns

the same mapping but without any nested namespace that is completely empty.

_update(*args, **kwds)

Update the values of the builder namespace passing a mapping as argument or individual keyword value pairs.

The method is prefixed with an underscore in order to not reserve the name for a potential port, but in principle the method functions just as collections.MutableMapping.update.

Parameters

• args (list) – a single mapping that should be mapped on the namespace

• kwds (dict) – keyword value pairs that should be mapped onto the ports

A namedtuple and namespace for ExitCodes that can be used to exit from Processes.

class aiida.engine.processes.exit_code.ExitCode(status, message)

Bases: tuple

__getnewargs__()

Return self as a plain tuple. Used by copy and pickle.

__module__ = 'aiida.engine.processes.exit_code'

static __new__(_cls, status=0, message=None)

Create new instance of ExitCode(status, message)

__repr__()

Return a nicely formatted representation string

__slots__ = ()

_asdict()

Return a new OrderedDict which maps field names to their values.

_fields = ('status', 'message')

_fields_defaults = {}

classmethod _make(iterable)

Make a new ExitCode object from a sequence or iterable

_replace(**kwds)

Return a new ExitCode object replacing specified fields with new values

property message

Alias for field number 1

property status

Alias for field number 0

class aiida.engine.processes.exit_code.ExitCodesNamespace(dictionary=None)

Bases: aiida.common.extendeddicts.AttributeDict

A namespace of ExitCode tuples that can be accessed through getattr as well as getitem. Additionally, the collection can be called with an identifier, that can either reference the integer status of the ExitCode that needs to be retrieved or the key in the collection

__call__(identifier)

Return a specific exit code identified by either its exit status or label

Parameters

identifier (str) – the identifier of the exit code. If the type is integer, it will be interpreted as the exit code status, otherwise it be interpreted as the exit code label

Returns

an ExitCode named tuple

Return type

aiida.engine.ExitCode

Raises

ValueError – if no exit code with the given label is defined for this process

__module__ = 'aiida.engine.processes.exit_code'

Class and decorators to generate processes out of simple python functions.

aiida.engine.processes.functions.calcfunction(function)

A decorator to turn a standard python function into a calcfunction. Example usage:

>>> from aiida.orm import Int
>>>
>>> # Define the calcfunction
>>> @calcfunction
>>> def sum(a, b):
>>>    return a + b
>>> # Run it with some input
>>> r = sum(Int(4), Int(5))
>>> print(r)
9
>>> r.get_incoming().all() 
[Neighbor(link_type='', link_label='result',
node=<CalcFunctionNode: uuid: ce0c63b3-1c84-4bb8-ba64-7b70a36adf34 (pk: 3567)>)]
>>> r.get_incoming().get_node_by_label('result').get_incoming().all_nodes()
[4, 5]

Parameters

function (callable) – The function to decorate.

Returns

The decorated function.

Return type

callable

aiida.engine.processes.functions.workfunction(function)

A decorator to turn a standard python function into a workfunction. Example usage:

>>> from aiida.orm import Int
>>>
>>> # Define the workfunction
>>> @workfunction
>>> def select(a, b):
>>>    return a
>>> # Run it with some input
>>> r = select(Int(4), Int(5))
>>> print(r)
4
>>> r.get_incoming().all() 
[Neighbor(link_type='', link_label='result',
node=<WorkFunctionNode: uuid: ce0c63b3-1c84-4bb8-ba64-7b70a36adf34 (pk: 3567)>)]
>>> r.get_incoming().get_node_by_label('result').get_incoming().all_nodes()
[4, 5]

Parameters

function (callable) – The function to decorate.

Returns

The decorated function.

Return type

callable

class aiida.engine.processes.functions.FunctionProcess(*args, **kwargs)

Bases: aiida.engine.processes.process.Process

Function process class used for turning functions into a Process

_Process__called = True

__abstractmethods__ = frozenset({})

__init__(*args, **kwargs)

Process constructor.

Parameters

• inputs (dict) – process inputs

• logger (logging.Logger) – aiida logger

• runner – process runner

• parent_pid (int) – id of parent process

• enable_persistence (bool) – whether to persist this process

Type

aiida.engine.runners.Runner

__module__ = 'aiida.engine.processes.functions'

_abc_impl = <_abc_data object>

static _func(*_args, **_kwargs)

This is used internally to store the actual function that is being wrapped and will be replaced by the build method.

_func_args = None

_setup_db_record()

Set up the database record for the process.

_spec = <aiida.engine.processes.process_spec.ProcessSpec object>

classmethod args_to_dict(*args)

Create an input dictionary (of form label -> value) from supplied args.

Parameters

args (list) – The values to use for the dictionary

Returns

A label -> value dictionary

Return type

dict

static build(func, node_class)

Build a Process from the given function.

All function arguments will be assigned as process inputs. If keyword arguments are specified then these will also become inputs.

Parameters

• func (callable) – The function to build a process from

• node_class (aiida.orm.nodes.process.process.ProcessNode) – Provide a custom node class to be used, has to be constructable with no arguments. It has to be a sub class of ProcessNode and the mixin FunctionCalculationMixin.

Returns

A Process class that represents the function

Return type

FunctionProcess

classmethod create_inputs(*args, **kwargs)

Create the input args for the FunctionProcess.

Return type

dict

execute()

Execute the process.

classmethod get_or_create_db_record()

Create a process node that represents what happened in this process.

Returns

A process node

Return type

aiida.orm.ProcessNode

property process_class

Return the class that represents this Process, for the FunctionProcess this is the function itself.

For a standard Process or sub class of Process, this is the class itself. However, for legacy reasons, the Process class is a wrapper around another class. This function returns that original class, i.e. the class that really represents what was being executed.

Returns

A Process class that represents the function

Return type

FunctionProcess

run()

Run the process.

Return type

aiida.engine.ExitCode

classmethod validate_inputs(*args, **kwargs)

Validate the positional and keyword arguments passed in the function call.

Raises

TypeError – if more positional arguments are passed than the function defines

Futures that can poll or receive broadcasted messages while waiting for a task to be completed.

class aiida.engine.processes.futures.CalculationFuture(pk, loop=None, poll_interval=None, communicator=None)

Bases: plumpy.futures.Future

A future that waits for a calculation to complete using both polling and listening for broadcast events if possible

__init__(pk, loop=None, poll_interval=None, communicator=None)

Get a future for a calculation node being finished. If a None poll_interval is supplied polling will not be used. If a communicator is supplied it will be used to listen for broadcast messages.

Parameters

• pk – The calculation pk

• loop – An event loop

• poll_interval – The polling interval. Can be None in which case no polling.

• communicator – A communicator. Can be None in which case no broadcast listens.

__module__ = 'aiida.engine.processes.futures'

_filtered = None

_poll_calculation(calc_node, poll_interval)

Poll whether the calculation node has reached a terminal state.

cleanup()

Clean up the future by removing broadcast subscribers from the communicator if it still exists.

AiiDA specific implementation of plumpy Ports and PortNamespaces for the ProcessSpec.

class aiida.engine.processes.ports.PortNamespace(*args, **kwargs)

Bases: aiida.engine.processes.ports.WithNonDb, plumpy.ports.PortNamespace

Sub class of plumpy.PortNamespace which implements the serialize method to support automatic recursive serialization of a given mapping onto the ports of the PortNamespace.

__abstractmethods__ = frozenset({})

__module__ = 'aiida.engine.processes.ports'

__setitem__(key, port)

Ensure that a Port being added inherits the non_db attribute if not explicitly defined at construction.

The reasoning is that if a PortNamespace has non_db=True, which is different from the default value, very often all leaves should be also non_db=True. To prevent a user from having to specify it manually everytime we overload the value here, unless it was specifically set during construction.

Note that the non_db attribute is not present for all Port sub classes so we have to check for it first.

__slotnames__ = []

_abc_impl = <_abc_data object>

serialize(mapping, breadcrumbs=())

Serialize the given mapping onto this Portnamespace.

It will recursively call this function on any nested PortNamespace or the serialize function on any Ports.

Parameters

• mapping – a mapping of values to be serialized

• breadcrumbs – a tuple with the namespaces of parent namespaces

Returns

the serialized mapping

static validate_port_name(port_name)

Validate the given port name.

Valid port names adhere to the following restrictions:

• Is a valid link label (see below)

• Does not contain two or more consecutive underscores

Valid link labels adhere to the following restrictions:

• Has to be a valid python identifier

• Can only contain alphanumeric characters and underscores

• Can not start or end with an underscore

Parameters

port_name – the proposed name of the port to be added

Raises

• TypeError – if the port name is not a string type

• ValueError – if the port name is invalid

class aiida.engine.processes.ports.InputPort(*args, **kwargs)

Bases: aiida.engine.processes.ports.WithSerialize, aiida.engine.processes.ports.WithNonDb, plumpy.ports.InputPort

Sub class of plumpy.InputPort which mixes in the WithSerialize and WithNonDb mixins to support automatic value serialization to database storable types and support non database storable input types as well.

__abstractmethods__ = frozenset({})

__module__ = 'aiida.engine.processes.ports'

__slotnames__ = []

_abc_impl = <_abc_data object>

get_description()

Return a description of the InputPort, which will be a dictionary of its attributes

Returns

a dictionary of the stringified InputPort attributes

class aiida.engine.processes.ports.OutputPort(name, valid_type=None, help=None, required=True, validator=None)

Bases: plumpy.ports.Port

__abstractmethods__ = frozenset({})

__module__ = 'plumpy.ports'

__slotnames__ = []

_abc_impl = <_abc_data object>

class aiida.engine.processes.ports.CalcJobOutputPort(*args, **kwargs)

Bases: plumpy.ports.OutputPort

Sub class of plumpy.OutputPort which adds the _pass_to_parser attribute.

__abstractmethods__ = frozenset({})

__init__(*args, **kwargs)

Initialize self. See help(type(self)) for accurate signature.

__module__ = 'aiida.engine.processes.ports'

_abc_impl = <_abc_data object>

property pass_to_parser

class aiida.engine.processes.ports.WithNonDb(*args, **kwargs)

Bases: object

A mixin that adds support to a port to flag a that should not be stored in the database using the non_db=True flag.

The mixins have to go before the main port class in the superclass order to make sure the mixin has the chance to strip out the non_db keyword.

__dict__ = mappingproxy({'__module__': 'aiida.engine.processes.ports', '__doc__': '\n A mixin that adds support to a port to flag a that should not be stored\n in the database using the non_db=True flag.\n\n The mixins have to go before the main port class in the superclass order\n to make sure the mixin has the chance to strip out the non_db keyword.\n ', '__init__': <function WithNonDb.__init__>, 'non_db_explicitly_set': <property object>, 'non_db': <property object>, '__dict__': <attribute '__dict__' of 'WithNonDb' objects>, '__weakref__': <attribute '__weakref__' of 'WithNonDb' objects>})

__init__(*args, **kwargs)

Initialize self. See help(type(self)) for accurate signature.

__module__ = 'aiida.engine.processes.ports'

__weakref__

list of weak references to the object (if defined)

property non_db

Return whether the value of this Port should be stored as a Node in the database.

Returns

boolean, True if it should be storable as a Node, False otherwise

property non_db_explicitly_set

Return whether the a value for non_db was explicitly passed in the construction of the Port.

Returns

boolean, True if non_db was explicitly defined during construction, False otherwise

class aiida.engine.processes.ports.WithSerialize(*args, **kwargs)

Bases: object

A mixin that adds support for a serialization function which is automatically applied on inputs that are not AiiDA data types.

__dict__ = mappingproxy({'__module__': 'aiida.engine.processes.ports', '__doc__': '\n A mixin that adds support for a serialization function which is automatically applied on inputs\n that are not AiiDA data types.\n ', '__init__': <function WithSerialize.__init__>, 'serialize': <function WithSerialize.serialize>, '__dict__': <attribute '__dict__' of 'WithSerialize' objects>, '__weakref__': <attribute '__weakref__' of 'WithSerialize' objects>})

__init__(*args, **kwargs)

Initialize self. See help(type(self)) for accurate signature.

__module__ = 'aiida.engine.processes.ports'

__weakref__

list of weak references to the object (if defined)

serialize(value)

Serialize the given value if it is not already a Data type and a serializer function is defined

Parameters

value – the value to be serialized

Returns

a serialized version of the value or the unchanged value

The AiiDA process class

class aiida.engine.processes.process.Process(inputs=None, logger=None, runner=None, parent_pid=None, enable_persistence=True)

Bases: plumpy.processes.Process

This class represents an AiiDA process which can be executed and will have full provenance saved in the database.

SINGLE_OUTPUT_LINKNAME = 'result'

class SaveKeys

Bases: enum.Enum

Keys used to identify things in the saved instance state bundle.

CALC_ID = 'calc_id'

__module__ = 'aiida.engine.processes.process'

_Process__called = True

__abstractmethods__ = frozenset({})

__init__(inputs=None, logger=None, runner=None, parent_pid=None, enable_persistence=True)

Process constructor.

Parameters

• inputs (dict) – process inputs

• logger (logging.Logger) – aiida logger

• runner – process runner

• parent_pid (int) – id of parent process

• enable_persistence (bool) – whether to persist this process

Type

aiida.engine.runners.Runner

__module__ = 'aiida.engine.processes.process'

_abc_impl = <_abc_data object>

_auto_persist = {'_CREATION_TIME', '_enable_persistence', '_future', '_parent_pid', '_paused', '_pid', '_pre_paused_status', '_status'}

_create_and_setup_db_record()

Create and setup the database record for this process

Returns

the uuid of the process

Return type

uuid.UUID

_flat_inputs()

Return a flattened version of the parsed inputs dictionary.

The eventual keys will be a concatenation of the nested keys. Note that the metadata dictionary, if present, is not passed, as those are dealt with separately in _setup_metadata.

Returns

flat dictionary of parsed inputs

Return type

dict

_flat_outputs()

Return a flattened version of the registered outputs dictionary.

The eventual keys will be a concatenation of the nested keys.

Returns

flat dictionary of parsed outputs

_flatten_inputs(port, port_value, parent_name='', separator='__')

Function that will recursively flatten the inputs dictionary, omitting inputs for ports that are marked as being non database storable

Parameters

• port (plumpy.ports.Port) – port against which to map the port value, can be InputPort or PortNamespace

• port_value – value for the current port, can be a Mapping

• parent_name (str) – the parent key with which to prefix the keys

• separator (str) – character to use for the concatenation of keys

Returns

flat list of inputs

Return type

list

_flatten_outputs(port, port_value, parent_name='', separator='__')

Function that will recursively flatten the outputs dictionary.

Parameters

• port (plumpy.ports.Port) – port against which to map the port value, can be OutputPort or PortNamespace

• port_value – value for the current port, can be a Mapping

• parent_name (str) – the parent key with which to prefix the keys

• separator (str) – character to use for the concatenation of keys

Returns

flat list of outputs

Return type

list

static _get_namespace_list(namespace=None, agglomerate=True)

Get the list of namespaces in a given namespace.

Parameters

• namespace (str) – name space

• agglomerate (bool) – If set to true, all parent namespaces of the given namespace will also be searched.

Returns

namespace list

Return type

list

_node_class

alias of aiida.orm.nodes.process.process.ProcessNode

_save_checkpoint()

Save the current state in a chechpoint if persistence is enabled and the process state is not terminal

If the persistence call excepts with a PersistenceError, it will be caught and a warning will be logged.

_setup_db_record()

Create the database record for this process and the links with respect to its inputs

This function will set various attributes on the node that serve as a proxy for attributes of the Process. This is essential as otherwise this information could only be introspected through the Process itself, which is only available to the interpreter that has it in memory. To make this data introspectable from any interpreter, for example for the command line interface, certain Process attributes are proxied through the calculation node.

In addition, the parent calculation will be setup with a CALL link if applicable and all inputs will be linked up as well.

_setup_inputs()

Create the links between the input nodes and the ProcessNode that represents this process.

_setup_metadata()

Store the metadata on the ProcessNode.

_spec = <aiida.engine.processes.process_spec.ProcessSpec object>

_spec_class

alias of aiida.engine.processes.process_spec.ProcessSpec

classmethod build_process_type()

The process type.

Returns

string of the process type

Return type

str

Note: This could be made into a property ‘process_type’ but in order to have it be a property of the class it would need to be defined in the metaclass, see https://bugs.python.org/issue20659

decode_input_args(encoded)

Decode saved input arguments as they came from the saved instance state Bundle

Parameters

encoded – encoded (serialized) inputs

Returns

The decoded input args

classmethod define(spec)

encode_input_args(inputs)

Encode input arguments such that they may be saved in a Bundle

Parameters

inputs – A mapping of the inputs as passed to the process

Returns

The encoded (serialized) inputs

exit_codes = {'ERROR_INVALID_OUTPUT': ExitCode(status=10, message='The process returned an invalid output.'), 'ERROR_LEGACY_FAILURE': ExitCode(status=2, message='The process failed with legacy failure mode.'), 'ERROR_MISSING_OUTPUT': ExitCode(status=11, message='The process did not register a required output.'), 'ERROR_UNSPECIFIED': ExitCode(status=1, message='The process has failed with an unspecified error.')}

exposed_inputs(process_class, namespace=None, agglomerate=True)

Gather a dictionary of the inputs that were exposed for a given Process class under an optional namespace.

Parameters

• process_class (aiida.engine.Process) – Process class whose inputs to try and retrieve

• namespace (str) – PortNamespace in which to look for the inputs

• agglomerate (bool) – If set to true, all parent namespaces of the given namespace will also be searched for inputs. Inputs in lower-lying namespaces take precedence.

Returns

exposed inputs

Return type

dict

exposed_outputs(node, process_class, namespace=None, agglomerate=True)

Return the outputs which were exposed from the process_class and emitted by the specific node

Parameters

• node (aiida.orm.nodes.process.ProcessNode) – process node whose outputs to try and retrieve

• namespace (str) – Namespace in which to search for exposed outputs.

• agglomerate (bool) – If set to true, all parent namespaces of the given namespace will also be searched for outputs. Outputs in lower-lying namespaces take precedence.

Returns

exposed outputs

Return type

dict

classmethod get_builder()

classmethod get_exit_statuses(exit_code_labels)

Return the exit status (integers) for the given exit code labels.

Parameters

exit_code_labels – a list of strings that reference exit code labels of this process class

Returns

list of exit status integers that correspond to the given exit code labels

Raises

AttributeError – if at least one of the labels does not correspond to an existing exit code

classmethod get_or_create_db_record()

Create a process node that represents what happened in this process.

Returns

A process node

Return type

aiida.orm.ProcessNode

get_parent_calc()

Get the parent process node

Returns

the parent process node if there is one

Return type

aiida.orm.ProcessNode

get_provenance_inputs_iterator()

Get provenance input iterator.

Return type

filter

init()

kill(msg=None)

Kill the process and all the children calculations it called

Parameters

msg (str) – message

Return type

bool

load_instance_state(saved_state, load_context)

Load instance state.

Parameters

• saved_state – saved instance state

• load_context (plumpy.persistence.LoadSaveContext) –

property metadata

Return the metadata that were specified when this process instance was launched.

Returns

metadata dictionary

Return type

dict

property node

Return the ProcessNode used by this process to represent itself in the database.

Returns

instance of sub class of ProcessNode

Return type

aiida.orm.ProcessNode

on_create()

Called when a Process is created.

on_entered(from_state)

on_entering(state)

on_except(exc_info)

Log the exception by calling the report method with formatted stack trace from exception info object and store the exception string as a node attribute

Parameters

exc_info – the sys.exc_info() object (type, value, traceback)

on_finish(result, successful)

Set the finish status on the process node.

Parameters

• result (int or aiida.engine.ExitCode) – result of the process

• successful (bool) – whether execution was successful

on_output_emitting(output_port, value)

The process has emitted a value on the given output port.

Parameters

• output_port (str) – The output port name the value was emitted on

• value – The value emitted

on_paused(msg=None)

The Process was paused so set the paused attribute on the process node

Parameters

msg (str) – message

on_playing()

The Process was unpaused so remove the paused attribute on the process node

on_terminated()

Called when a Process enters a terminal state.

out(output_port, value=None)

Attach output to output port.

The name of the port will be used as the link label.

Parameters

• output_port (str) – name of output port

• value – value to put inside output port

out_many(out_dict)

Attach outputs to multiple output ports.

Keys of the dictionary will be used as output port names, values as outputs.

Parameters

out_dict (dict) – output dictionary

report(msg, *args, **kwargs)

Log a message to the logger, which should get saved to the database through the attached DbLogHandler.

The pk, class name and function name of the caller are prepended to the given message

Parameters

• msg (str) – message to log

• args (list) – args to pass to the log call

• kwargs (dict) – kwargs to pass to the log call

property runner

Get process runner.

Return type

aiida.engine.runners.Runner

save_instance_state(out_state, save_context)

Save instance state.

See documentation of plumpy.processes.Process.save_instance_state().

set_status(status)

The status of the Process is about to be changed, so we reflect this is in node’s attribute proxy.

Parameters

status (str) – the status message

spec_metadata = <aiida.engine.processes.ports.PortNamespace object>

submit(process, *args, **kwargs)

Submit process for execution.

Parameters

process (aiida.engine.Process) – process

update_node_state(state)

update_outputs()

Attach new outputs to the node since the last call.

Does nothing, if self.metadata.store_provenance is False.

property uuid

Return the UUID of the process which corresponds to the UUID of its associated ProcessNode.

Returns

the UUID associated to this process instance

class aiida.engine.processes.process.ProcessState

Bases: enum.Enum

The possible states that a Process can be in.

CREATED = 'created'

EXCEPTED = 'excepted'

FINISHED = 'finished'

KILLED = 'killed'

RUNNING = 'running'

WAITING = 'waiting'

__module__ = 'plumpy.process_states'

AiiDA specific implementation of plumpy’s ProcessSpec.

class aiida.engine.processes.process_spec.CalcJobProcessSpec

Bases: aiida.engine.processes.process_spec.ProcessSpec

Process spec intended for the CalcJob process class.

OUTPUT_PORT_TYPE

alias of aiida.engine.processes.ports.CalcJobOutputPort

__init__()

Initialize self. See help(type(self)) for accurate signature.

__module__ = 'aiida.engine.processes.process_spec'

property default_output_node

class aiida.engine.processes.process_spec.ProcessSpec

Bases: plumpy.process_spec.ProcessSpec

Default process spec for process classes defined in aiida-core.

This sub class defines custom classes for input ports and port namespaces. It also adds support for the definition of exit codes and retrieving them subsequently.

INPUT_PORT_TYPE

alias of aiida.engine.processes.ports.InputPort

METADATA_KEY = 'metadata'

METADATA_OPTIONS_KEY = 'options'

PORT_NAMESPACE_TYPE

alias of aiida.engine.processes.ports.PortNamespace

__init__()

Initialize self. See help(type(self)) for accurate signature.

__module__ = 'aiida.engine.processes.process_spec'

exit_code(status, label, message)

Add an exit code to the ProcessSpec

Parameters

• status – the exit status integer

• label – a label by which the exit code can be addressed

• message – a more detailed description of the exit code

property exit_codes

Return the namespace of exit codes defined for this ProcessSpec

Returns

ExitCodesNamespace of ExitCode named tuples

property metadata_key

property options_key