flytekit.core.base_task

============================== :mod:flytekit.core.base_task

.. currentmodule:: flytekit.core.base_task

.. autosummary:: :nosignatures: :template: custom.rst :toctree: generated/

kwtypes PythonTask Task TaskResolverMixin IgnoreOutputs

Directory

Classes

Errors

• FlyteDownloadDataException
• FlyteNonRecoverableSystemException
• FlyteUploadDataException
• FlyteUserRuntimeException
• IgnoreOutputs
• TypeTransformerFailedError

flytekit.core.base_task.Any

Special type indicating an unconstrained type.

• Any is compatible with every type.
• Any assumed to have all methods.
• All values assumed to be instances of Any.

Note that all the above statements are true from the point of view of static type checkers. At runtime, Any should not be used with instance checks.

flytekit.core.base_task.DeckField

DeckField is used to specify the fields that will be rendered in the deck.

def DeckField(
    args,
    kwds,
):

flytekit.core.base_task.Description

Full user description with formatting preserved. This can be rendered by clients, such as the console or command line tools with in-tact formatting.

def Description(
    value: typing.Optional[str],
    uri: typing.Optional[str],
    icon_link: typing.Optional[str],
    format: <enum 'DescriptionFormat'>,
):

Methods

from_flyte_idl()

def from_flyte_idl(
    pb2_object: flyteidl.admin.description_entity_pb2.Description,
):

serialize_to_string()

def serialize_to_string()

short_string()

def short_string()

to_flyte_idl()

def to_flyte_idl()

verbose_string()

def verbose_string()

Properties

flytekit.core.base_task.Documentation

DescriptionEntity contains detailed description for the task/workflow/launch plan. Documentation could provide insight into the algorithms, business use case, etc.

def Documentation(
    short_description: typing.Optional[str],
    long_description: typing.Optional[flytekit.models.documentation.Description],
    source_code: typing.Optional[flytekit.models.documentation.SourceCode],
):

Methods

from_flyte_idl()

def from_flyte_idl(
    pb2_object: flyteidl.admin.description_entity_pb2.DescriptionEntity,
):

serialize_to_string()

def serialize_to_string()

short_string()

def short_string()

to_flyte_idl()

def to_flyte_idl()

verbose_string()

def verbose_string()

Properties

flytekit.core.base_task.ExecutionParameters

This is a run-time user-centric context object that is accessible to every @task method. It can be accessed using

.. code-block:: python

flytekit.current_context()

This object provides the following

• a statsd handler
• a logging handler
• the execution ID as an :py:class:flytekit.models.core.identifier.WorkflowExecutionIdentifier object
• a working directory for the user to write arbitrary files to

Please do not confuse this object with the :py:class:flytekit.FlyteContext object.

def ExecutionParameters(
    execution_date,
    tmp_dir,
    stats,
    execution_id: typing.Optional[_identifier.WorkflowExecutionIdentifier],
    logging,
    raw_output_prefix,
    output_metadata_prefix,
    checkpoint,
    decks,
    task_id: typing.Optional[_identifier.Identifier],
    enable_deck: bool,
    kwargs,
):

Methods

builder()

def builder()

get()

def get(
    key: str,
):

Returns task specific context if present else raise an error. The returned context will match the key

has_attr()

def has_attr(
    attr_name: str,
):

new_builder()

def new_builder(
    current: Optional[ExecutionParameters],
):

with_enable_deck()

def with_enable_deck(
    enable_deck: bool,
):

with_task_sandbox()

def with_task_sandbox()

Properties

flytekit.core.base_task.ExecutionState

This is the context that is active when executing a task or a local workflow. This carries the necessary state to execute. Some required things during execution deal with temporary directories, ExecutionParameters that are passed to the user etc.

Attributes: mode (ExecutionState.Mode): Defines the context in which the task is executed (local, hosted, etc). working_dir (os.PathLike): Specifies the remote, external directory where inputs, outputs and other protobufs are uploaded engine_dir (os.PathLike): branch_eval_mode Optional[BranchEvalMode]: Used to determine whether a branch node should execute. user_space_params Optional[ExecutionParameters]: Provides run-time, user-centric context such as a statsd handler, a logging handler, the current execution id and a working directory.

def ExecutionState(
    working_dir: Union[os.PathLike, str],
    mode: Optional[ExecutionState.Mode],
    engine_dir: Optional[Union[os.PathLike, str]],
    branch_eval_mode: Optional[BranchEvalMode],
    user_space_params: Optional[ExecutionParameters],
):

Methods

branch_complete()

def branch_complete()

Indicates that we are within a conditional / ifelse block and the active branch is not done. Default to SKIPPED

is_local_execution()

def is_local_execution()

take_branch()

def take_branch()

Indicates that we are within an if-else block and the current branch has evaluated to true. Useful only in local execution mode

with_params()

def with_params(
    working_dir: Optional[os.PathLike],
    mode: Optional[Mode],
    engine_dir: Optional[os.PathLike],
    branch_eval_mode: Optional[BranchEvalMode],
    user_space_params: Optional[ExecutionParameters],
):

Produces a copy of the current execution state and overrides the copy’s parameters with passed parameter values.

flytekit.core.base_task.FlyteContext

This is an internal-facing context object, that most users will not have to deal with. It’s essentially a globally available grab bag of settings and objects that allows flytekit to do things like convert complex types, run and compile workflows, serialize Flyte entities, etc.

Even though this object as a current_context function on it, it should not be called directly. Please use the :py:class:flytekit.FlyteContextManager object instead.

Please do not confuse this object with the :py:class:flytekit.ExecutionParameters object.

def FlyteContext(
    file_access: FileAccessProvider,
    level: int,
    flyte_client: Optional['friendly_client.SynchronousFlyteClient'],
    compilation_state: Optional[CompilationState],
    execution_state: Optional[ExecutionState],
    serialization_settings: Optional[SerializationSettings],
    in_a_condition: bool,
    origin_stackframe: Optional[traceback.FrameSummary],
    output_metadata_tracker: Optional[OutputMetadataTracker],
    worker_queue: Optional[Controller],
):

Methods

current_context()

def current_context()

This method exists only to maintain backwards compatibility. Please use FlyteContextManager.current_context() instead.

Users of flytekit should be wary not to confuse the object returned from this function with :py:func:flytekit.current_context

enter_conditional_section()

def enter_conditional_section()

get_deck()

def get_deck()

Returns the deck that was created as part of the last execution.

The return value depends on the execution environment. In a notebook, the return value is compatible with IPython.display and should be rendered in the notebook.

.. code-block:: python

with flytekit.new_context() as ctx: my_task(…) ctx.get_deck()

OR if you wish to explicitly display

.. code-block:: python

from IPython import display display(ctx.get_deck())

get_origin_stackframe_repr()

def get_origin_stackframe_repr()

new_builder()

def new_builder()

new_compilation_state()

def new_compilation_state(
    prefix: str,
):

Creates and returns a default compilation state. For most of the code this should be the entrypoint of compilation, otherwise the code should always uses - with_compilation_state

new_execution_state()

def new_execution_state(
    working_dir: Optional[os.PathLike],
):

Creates and returns a new default execution state. This should be used at the entrypoint of execution, in all other cases it is preferable to use with_execution_state

set_stackframe()

def set_stackframe(
    s: traceback.FrameSummary,
):

with_client()

def with_client(
    c: SynchronousFlyteClient,
):

with_compilation_state()

def with_compilation_state(
    c: CompilationState,
):

with_execution_state()

def with_execution_state(
    es: ExecutionState,
):

with_file_access()

def with_file_access(
    fa: FileAccessProvider,
):

with_new_compilation_state()

def with_new_compilation_state()

with_output_metadata_tracker()

def with_output_metadata_tracker(
    t: OutputMetadataTracker,
):

with_serialization_settings()

def with_serialization_settings(
    ss: SerializationSettings,
):

with_worker_queue()

def with_worker_queue(
    wq: Controller,
):

Properties

flytekit.core.base_task.FlyteContextManager

FlyteContextManager manages the execution context within Flytekit. It holds global state of either compilation or Execution. It is not thread-safe and can only be run as a single threaded application currently. Context’s within Flytekit is useful to manage compilation state and execution state. Refer to CompilationState and ExecutionState for more information. FlyteContextManager provides a singleton stack to manage these contexts.

Typical usage is

.. code-block:: python

FlyteContextManager.initialize() with FlyteContextManager.with_context(o) as ctx: pass

If required - not recommended you can use

FlyteContextManager.push_context()

but correspondingly a pop_context should be called

FlyteContextManager.pop_context()

Methods

add_signal_handler()

def add_signal_handler(
    handler: typing.Callable[[int, FrameType], typing.Any],
):

current_context()

def current_context()

get_origin_stackframe()

def get_origin_stackframe(
    limit,
):

initialize()

def initialize()

Re-initializes the context and erases the entire context

pop_context()

def pop_context()

push_context()

def push_context(
    ctx: FlyteContext,
    f: Optional[traceback.FrameSummary],
):

size()

def size()

with_context()

def with_context(
    b: FlyteContext.Builder,
):

flytekit.core.base_task.FlyteDownloadDataException

Common base class for all non-exit exceptions.

def FlyteDownloadDataException(
    args,
    timestamp: typing.Optional[float],
):

Properties

flytekit.core.base_task.FlyteEntities

This is a global Object that tracks various tasks and workflows that are declared within a VM during the registration process

flytekit.core.base_task.FlyteNonRecoverableSystemException

Common base class for all non-exit exceptions.

def FlyteNonRecoverableSystemException(
    exc_value: Exception,
):

FlyteNonRecoverableSystemException is thrown when a system code raises an exception.

Properties

flytekit.core.base_task.FlyteUploadDataException

Common base class for all non-exit exceptions.

def FlyteUploadDataException(
    args,
    timestamp: typing.Optional[float],
):

Properties

flytekit.core.base_task.FlyteUserRuntimeException

Common base class for all non-exit exceptions.

def FlyteUserRuntimeException(
    exc_value: Exception,
    timestamp: typing.Optional[float],
):

FlyteUserRuntimeException is thrown when a user code raises an exception.

Properties

flytekit.core.base_task.Generic

Abstract base class for generic types.

On Python 3.12 and newer, generic classes implicitly inherit from Generic when they declare a parameter list after the class’s name::

class Mapping[KT, VT]: def getitem(self, key: KT) -> VT: …

Etc.

On older versions of Python, however, generic classes have to explicitly inherit from Generic.

After a class has been declared to be generic, it can then be used as follows::

def lookup_name[KT, VT](mapping: Mapping[KT, VT], key: KT, default: VT) -> VT: try: return mapping[key] except KeyError: return default

flytekit.core.base_task.IgnoreOutputs

This exception should be used to indicate that the outputs generated by this can be safely ignored. This is useful in case of distributed training or peer-to-peer parallel algorithms.

flytekit.core.base_task.Interface

A Python native interface object, like inspect.signature but simpler.

def Interface(
    inputs: Union[Optional[Dict[str, Type]], Optional[Dict[str, Tuple[Type, Any]]]],
    outputs: Union[Optional[Dict[str, Type]], Optional[Dict[str, Optional[Type]]]],
    output_tuple_name: Optional[str],
    docstring: Optional[Docstring],
):

Methods

remove_inputs()

def remove_inputs(
    vars: Optional[List[str]],
):

This method is useful in removing some variables from the Flyte backend inputs specification, as these are implicit local only inputs or will be supplied by the library at runtime. For example, spark-session etc It creates a new instance of interface with the requested variables removed

with_inputs()

def with_inputs(
    extra_inputs: Dict[str, Type],
):

Use this to add additional inputs to the interface. This is useful for adding additional implicit inputs that are added without the user requesting for them

with_outputs()

def with_outputs(
    extra_outputs: Dict[str, Type],
):

This method allows addition of extra outputs are expected from a task specification

Properties

flytekit.core.base_task.LocalConfig

Any configuration specific to local runs.

def LocalConfig(
    cache_enabled: bool,
    cache_overwrite: bool,
):

Methods

auto()

def auto(
    config_file: typing.Union[str, ConfigFile],
):

flytekit.core.base_task.LocalTaskCache

This class implements a persistent store able to cache the result of local task executions.

Methods

clear()

def clear()

get()

def get(
    task_name: str,
    cache_version: str,
    input_literal_map: flytekit.models.literals.LiteralMap,
    cache_ignore_input_vars: typing.Tuple[str, ...],
):

initialize()

def initialize()

set()

def set(
    task_name: str,
    cache_version: str,
    input_literal_map: flytekit.models.literals.LiteralMap,
    cache_ignore_input_vars: typing.Tuple[str, ...],
    value: flytekit.models.literals.LiteralMap,
):

flytekit.core.base_task.Promise

This object is a wrapper and exists for three main reasons. Let’s assume we’re dealing with a task like ::

@task def t1() -> (int, str): …

#. Handling the duality between compilation and local execution - when the task function is run in a local execution mode inside a workflow function, a Python integer and string are produced. When the task is being compiled as part of the workflow, the task call creates a Node instead, and the task returns two Promise objects that point to that Node. #. One needs to be able to call ::

x = t1().with_overrides(…)

If the task returns an integer or a (int, str) tuple like t1 above, calling with_overrides on the result would throw an error. This Promise object adds that. #. Assorted handling for conditionals.

def Promise(
    var: str,
    val: Union[NodeOutput, _literals_models.Literal],
    type: typing.Optional[_type_models.LiteralType],
):

Methods

deepcopy()

def deepcopy()

eval()

def eval()

is_()

def is_(
    v: bool,
):

is_false()

def is_false()

is_none()

def is_none()

is_true()

def is_true()

with_overrides()

def with_overrides(
    node_name: Optional[str],
    aliases: Optional[Dict[str, str]],
    requests: Optional[Resources],
    limits: Optional[Resources],
    timeout: Optional[Union[int, datetime.timedelta, object]],
    retries: Optional[int],
    interruptible: Optional[bool],
    name: Optional[str],
    task_config: Optional[Any],
    container_image: Optional[str],
    accelerator: Optional[BaseAccelerator],
    cache: Optional[bool],
    cache_version: Optional[str],
    cache_serialize: Optional[bool],
    args,
    kwargs,
):

with_var()

def with_var(
    new_var: str,
):

Properties

flytekit.core.base_task.PythonTask

Base Class for all Tasks with a Python native Interface. This should be directly used for task types, that do not have a python function to be executed. Otherwise refer to :py:class:flytekit.PythonFunctionTask.

def PythonTask(
    task_type: str,
    name: str,
    task_config: typing.Optional[~T],
    interface: typing.Optional[flytekit.core.interface.Interface],
    environment: typing.Optional[typing.Dict[str, str]],
    disable_deck: typing.Optional[bool],
    enable_deck: typing.Optional[bool],
    deck_fields: typing.Optional[typing.Tuple[flytekit.deck.deck.DeckField, ...]],
    kwargs,
):

Methods

compile()

def compile(
    ctx: flytekit.core.context_manager.FlyteContext,
    args,
    kwargs,
):

Generates a node that encapsulates this task in a workflow definition.

construct_node_metadata()

def construct_node_metadata()

Used when constructing the node that encapsulates this task as part of a broader workflow definition.

dispatch_execute()

def dispatch_execute(
    ctx: flytekit.core.context_manager.FlyteContext,
    input_literal_map: flytekit.models.literals.LiteralMap,
):

This method translates Flyte’s Type system based input values and invokes the actual call to the executor This method is also invoked during runtime.

• VoidPromise is returned in the case when the task itself declares no outputs.
• Literal Map is returned when the task returns either one more outputs in the declaration. Individual outputs may be none
• DynamicJobSpec is returned when a dynamic workflow is executed

execute()

def execute(
    kwargs,
):

This method will be invoked to execute the task.

find_lhs()

def find_lhs()

get_config()

def get_config(
    settings: flytekit.configuration.SerializationSettings,
):

Returns the task config as a serializable dictionary. This task config consists of metadata about the custom defined for this task.

get_container()

def get_container(
    settings: flytekit.configuration.SerializationSettings,
):

Returns the container definition (if any) that is used to run the task on hosted Flyte.

get_custom()

def get_custom(
    settings: flytekit.configuration.SerializationSettings,
):

Return additional plugin-specific custom data (if any) as a serializable dictionary.

get_extended_resources()

def get_extended_resources(
    settings: flytekit.configuration.SerializationSettings,
):

Returns the extended resources to allocate to the task on hosted Flyte.

get_input_types()

def get_input_types()

Returns the names and python types as a dictionary for the inputs of this task.

get_k8s_pod()

def get_k8s_pod(
    settings: flytekit.configuration.SerializationSettings,
):

Returns the kubernetes pod definition (if any) that is used to run the task on hosted Flyte.

get_sql()

def get_sql(
    settings: flytekit.configuration.SerializationSettings,
):

Returns the Sql definition (if any) that is used to run the task on hosted Flyte.

get_type_for_input_var()

def get_type_for_input_var(
    k: str,
    v: typing.Any,
):

Returns the python type for an input variable by name.

get_type_for_output_var()

def get_type_for_output_var(
    k: str,
    v: typing.Any,
):

Returns the python type for the specified output variable by name.

local_execute()

def local_execute(
    ctx: flytekit.core.context_manager.FlyteContext,
    kwargs,
):

This function is used only in the local execution path and is responsible for calling dispatch execute. Use this function when calling a task with native values (or Promises containing Flyte literals derived from Python native values).

local_execution_mode()

def local_execution_mode()

post_execute()

def post_execute(
    user_params: typing.Optional[flytekit.core.context_manager.ExecutionParameters],
    rval: typing.Any,
):

Post execute is called after the execution has completed, with the user_params and can be used to clean-up, or alter the outputs to match the intended tasks outputs. If not overridden, then this function is a No-op

pre_execute()

def pre_execute(
    user_params: typing.Optional[flytekit.core.context_manager.ExecutionParameters],
):

This is the method that will be invoked directly before executing the task method and before all the inputs are converted. One particular case where this is useful is if the context is to be modified for the user process to get some user space parameters. This also ensures that things like SparkSession are already correctly setup before the type transformers are called

This should return either the same context of the mutated context

sandbox_execute()

def sandbox_execute(
    ctx: flytekit.core.context_manager.FlyteContext,
    input_literal_map: flytekit.models.literals.LiteralMap,
):

Call dispatch_execute, in the context of a local sandbox execution. Not invoked during runtime.

Properties

flytekit.core.base_task.SecurityContext

This is a higher level wrapper object that for the most part users shouldn’t have to worry about. You should be able to just use :py:class:flytekit.Secret instead.

def SecurityContext(
    run_as: typing.Optional[flytekit.models.security.Identity],
    secrets: typing.Optional[typing.List[flytekit.models.security.Secret]],
    tokens: typing.Optional[typing.List[flytekit.models.security.OAuth2TokenRequest]],
):

Methods

from_flyte_idl()

def from_flyte_idl(
    pb2_object: flyteidl.core.security_pb2.SecurityContext,
):

serialize_to_string()

def serialize_to_string()

short_string()

def short_string()

to_flyte_idl()

def to_flyte_idl()

verbose_string()

def verbose_string()

Properties

flytekit.core.base_task.SerializationSettings

These settings are provided while serializing a workflow and task, before registration. This is required to get runtime information at serialization time, as well as some defaults.

Attributes: project (str): The project (if any) with which to register entities under. domain (str): The domain (if any) with which to register entities under. version (str): The version (if any) with which to register entities under. image_config (ImageConfig): The image config used to define task container images. env (Optional[Dict[str, str]]): Environment variables injected into task container definitions. flytekit_virtualenv_root (Optional[str]): During out of container serialize the absolute path of the flytekit virtualenv at serialization time won’t match the in-container value at execution time. This optional value is used to provide the in-container virtualenv path python_interpreter (Optional[str]): The python executable to use. This is used for spark tasks in out of container execution. entrypoint_settings (Optional[EntrypointSettings]): Information about the command, path and version of the entrypoint program. fast_serialization_settings (Optional[FastSerializationSettings]): If the code is being serialized so that it can be fast registered (and thus omit building a Docker image) this object contains additional parameters for serialization. source_root (Optional[str]): The root directory of the source code.

def SerializationSettings(
    image_config: ImageConfig,
    project: typing.Optional[str],
    domain: typing.Optional[str],
    version: typing.Optional[str],
    env: Optional[Dict[str, str]],
    git_repo: Optional[str],
    python_interpreter: str,
    flytekit_virtualenv_root: Optional[str],
    fast_serialization_settings: Optional[FastSerializationSettings],
    source_root: Optional[str],
):

Methods

default_entrypoint_settings()

def default_entrypoint_settings(
    interpreter_path: str,
):

Assumes the entrypoint is installed in a virtual-environment where the interpreter is

for_image()

def for_image(
    image: str,
    version: str,
    project: str,
    domain: str,
    python_interpreter_path: str,
):

from_dict()

def from_dict(
    kvs: typing.Union[dict, list, str, int, float, bool, NoneType],
    infer_missing,
):

from_json()

def from_json(
    s: typing.Union[str, bytes, bytearray],
    parse_float,
    parse_int,
    parse_constant,
    infer_missing,
    kw,
):

from_transport()

def from_transport(
    s: str,
):

new_builder()

def new_builder()

Creates a SerializationSettings.Builder that copies the existing serialization settings parameters and allows for customization.

schema()

def schema(
    infer_missing: bool,
    only,
    exclude,
    many: bool,
    context,
    load_only,
    dump_only,
    partial: bool,
    unknown,
):

should_fast_serialize()

def should_fast_serialize()

Whether or not the serialization settings specify that entities should be serialized for fast registration.

to_dict()

def to_dict(
    encode_json,
):

to_json()

def to_json(
    skipkeys: bool,
    ensure_ascii: bool,
    check_circular: bool,
    allow_nan: bool,
    indent: typing.Union[int, str, NoneType],
    separators: typing.Tuple[str, str],
    default: typing.Callable,
    sort_keys: bool,
    kw,
):

venv_root_from_interpreter()

def venv_root_from_interpreter(
    interpreter_path: str,
):

Computes the path of the virtual environment root, based on the passed in python interpreter path for example /opt/venv/bin/python3 -> /opt/venv

with_serialized_context()

def with_serialized_context()

Use this method to create a new SerializationSettings that has an environment variable set with the SerializedContext This is useful in transporting SerializedContext to serialized and registered tasks. The setting will be available in the env field with the key SERIALIZED_CONTEXT_ENV_VAR :return: A newly constructed SerializationSettings, or self, if it already has the serializationSettings

Properties

flytekit.core.base_task.Task

The base of all Tasks in flytekit. This task is closest to the FlyteIDL TaskTemplate and captures information in FlyteIDL specification and does not have python native interfaces associated. Refer to the derived classes for examples of how to extend this class.

def Task(
    task_type: str,
    name: str,
    interface: flytekit.models.interface.TypedInterface,
    metadata: typing.Optional[flytekit.core.base_task.TaskMetadata],
    task_type_version,
    security_ctx: typing.Optional[flytekit.models.security.SecurityContext],
    docs: typing.Optional[flytekit.models.documentation.Documentation],
    kwargs,
):

Methods

compile()

def compile(
    ctx: flytekit.core.context_manager.FlyteContext,
    args,
    kwargs,
):

dispatch_execute()

def dispatch_execute(
    ctx: flytekit.core.context_manager.FlyteContext,
    input_literal_map: flytekit.models.literals.LiteralMap,
):

This method translates Flyte’s Type system based input values and invokes the actual call to the executor This method is also invoked during runtime.

execute()

def execute(
    kwargs,
):

This method will be invoked to execute the task.

get_config()

def get_config(
    settings: flytekit.configuration.SerializationSettings,
):

Returns the task config as a serializable dictionary. This task config consists of metadata about the custom defined for this task.

get_container()

def get_container(
    settings: flytekit.configuration.SerializationSettings,
):

Returns the container definition (if any) that is used to run the task on hosted Flyte.

get_custom()

def get_custom(
    settings: flytekit.configuration.SerializationSettings,
):

Return additional plugin-specific custom data (if any) as a serializable dictionary.

get_extended_resources()

def get_extended_resources(
    settings: flytekit.configuration.SerializationSettings,
):

Returns the extended resources to allocate to the task on hosted Flyte.

get_input_types()

def get_input_types()

Returns python native types for inputs. In case this is not a python native task (base class) and hence returns a None. we could deduce the type from literal types, but that is not a required exercise

TODO we could use literal type to determine this

get_k8s_pod()

def get_k8s_pod(
    settings: flytekit.configuration.SerializationSettings,
):

Returns the kubernetes pod definition (if any) that is used to run the task on hosted Flyte.

get_sql()

def get_sql(
    settings: flytekit.configuration.SerializationSettings,
):

Returns the Sql definition (if any) that is used to run the task on hosted Flyte.

get_type_for_input_var()

def get_type_for_input_var(
    k: str,
    v: typing.Any,
):

Returns the python native type for the given input variable

TODO we could use literal type to determine this

get_type_for_output_var()

def get_type_for_output_var(
    k: str,
    v: typing.Any,
):

Returns the python native type for the given output variable

TODO we could use literal type to determine this

local_execute()

def local_execute(
    ctx: flytekit.core.context_manager.FlyteContext,
    kwargs,
):

This function is used only in the local execution path and is responsible for calling dispatch execute. Use this function when calling a task with native values (or Promises containing Flyte literals derived from Python native values).

local_execution_mode()

def local_execution_mode()

pre_execute()

def pre_execute(
    user_params: flytekit.core.context_manager.ExecutionParameters,
):

This is the method that will be invoked directly before executing the task method and before all the inputs are converted. One particular case where this is useful is if the context is to be modified for the user process to get some user space parameters. This also ensures that things like SparkSession are already correctly setup before the type transformers are called

This should return either the same context of the mutated context

sandbox_execute()

def sandbox_execute(
    ctx: flytekit.core.context_manager.FlyteContext,
    input_literal_map: flytekit.models.literals.LiteralMap,
):

Call dispatch_execute, in the context of a local sandbox execution. Not invoked during runtime.

Properties

flytekit.core.base_task.TaskMetadata

Metadata for a Task. Things like retries and whether or not caching is turned on, and cache version are specified here.

See the :std:ref:IDL <idl:protos/docs/core/core:taskmetadata> for the protobuf definition.

Attributes: cache (bool): Indicates if caching should be enabled. See :std:ref:Caching <cookbook:caching>. cache_serialize (bool): Indicates if identical (i.e. same inputs) instances of this task should be executed in serial when caching is enabled. See :std:ref:Caching <cookbook:caching>. cache_version (str): Version to be used for the cached value. cache_ignore_input_vars (Tuple[str, …]): Input variables that should not be included when calculating hash for cache. interruptible (Optional[bool]): Indicates that this task can be interrupted and/or scheduled on nodes with lower QoS guarantees that can include pre-emption. deprecated (str): Can be used to provide a warning message for a deprecated task. An absence or empty string indicates that the task is active and not deprecated. retries (int): for retries=n; n > 0, on failures of this task, the task will be retried at-least n number of times. timeout (Optional[Union[datetime.timedelta, int]]): The maximum duration for which one execution of this task should run. The execution will be terminated if the runtime exceeds this timeout. pod_template_name (Optional[str]): The name of an existing PodTemplate resource in the cluster which will be used for this task. generates_deck (bool): Indicates whether the task will generate a Deck URI. is_eager (bool): Indicates whether the task should be treated as eager.

def TaskMetadata(
    cache: bool,
    cache_serialize: bool,
    cache_version: str,
    cache_ignore_input_vars: typing.Tuple[str, ...],
    interruptible: typing.Optional[bool],
    deprecated: str,
    retries: int,
    timeout: typing.Union[datetime.timedelta, int, NoneType],
    pod_template_name: typing.Optional[str],
    generates_deck: bool,
    is_eager: bool,
):

Methods

to_taskmetadata_model()

def to_taskmetadata_model()

Converts to _task_model.TaskMetadata

Properties

flytekit.core.base_task.TaskResolverMixin

Flytekit tasks interact with the Flyte platform very, very broadly in two steps. They need to be uploaded to Admin, and then they are run by the user upon request (either as a single task execution or as part of a workflow). In any case, at execution time, for most tasks (that is those that generate a container target) the container image containing the task needs to be spun up again at which point the container needs to know which task it’s supposed to run and how to rehydrate the task object.

For example, the serialization of a simple task ::

in repo_root/workflows/example.py

@task def t1(…) -> …: …

might result in a container with arguments like ::

pyflyte-execute –inputs s3://path/inputs.pb –output-prefix s3://outputs/location –raw-output-data-prefix /tmp/data –resolver flytekit.core.python_auto_container.default_task_resolver – task-module repo_root.workflows.example task-name t1

At serialization time, the container created for the task will start out automatically with the pyflyte-execute bit, along with the requisite input/output args and the offloaded data prefix. Appended to that will be two things,

#. the location of the task’s task resolver, followed by two dashes, followed by #. the arguments provided by calling the loader_args function below.

The default_task_resolver declared below knows that

• When loader_args is called on a task, to look up the module the task is in, and the name of the task (the key of the task in the module, either the function name, or the variable it was assigned to).
• When load_task is called, it interprets the first part of the command as the module to call importlib.import_module on, and then looks for a key t1.

This is just the default behavior. Users should feel free to implement their own resolvers.

Methods

get_all_tasks()

def get_all_tasks()

Future proof method. Just making it easy to access all tasks (Not required today as we auto register them)

load_task()

def load_task(
    loader_args: typing.List[str],
):

Given the set of identifier keys, should return one Python Task or raise an error if not found

loader_args()

def loader_args(
    settings: flytekit.configuration.SerializationSettings,
    t: flytekit.core.base_task.Task,
):

Return a list of strings that can help identify the parameter Task

name()

def name()

task_name()

def task_name(
    t: flytekit.core.base_task.Task,
):

Overridable function that can optionally return a custom name for a given task

Properties

flytekit.core.base_task.TrackedInstance

Please see the notes for the metaclass above first.

This functionality has two use-cases currently,

• Keep track of naming for non-function PythonAutoContainerTasks. That is, things like the :py:class:flytekit.extras.sqlite3.task.SQLite3Task task.
• Task resolvers, because task resolvers are instances of :py:class:flytekit.core.python_auto_container.TaskResolverMixin classes, not the classes themselves, which means we need to look on the left hand side of them to see how to find them at task execution time.

def TrackedInstance(
    args,
    kwargs,
):

Methods

find_lhs()

def find_lhs()

Properties

flytekit.core.base_task.TypeEngine

Core Extensible TypeEngine of Flytekit. This should be used to extend the capabilities of FlyteKits type system. Users can implement their own TypeTransformers and register them with the TypeEngine. This will allow special handling of user objects

Methods

async_to_literal()

def async_to_literal(
    ctx: FlyteContext,
    python_val: typing.Any,
    python_type: Type[T],
    expected: LiteralType,
):

Converts a python value of a given type and expected LiteralType into a resolved Literal value.

async_to_python_value()

def async_to_python_value(
    ctx: FlyteContext,
    lv: Literal,
    expected_python_type: Type,
):

calculate_hash()

def calculate_hash(
    python_val: typing.Any,
    python_type: Type[T],
):

dict_to_literal_map()

def dict_to_literal_map(
    ctx: FlyteContext,
    d: typing.Dict[str, typing.Any],
    type_hints: Optional[typing.Dict[str, type]],
):

dict_to_literal_map_pb()

def dict_to_literal_map_pb(
    ctx: FlyteContext,
    d: typing.Dict[str, typing.Any],
    type_hints: Optional[typing.Dict[str, type]],
):

get_available_transformers()

def get_available_transformers()

Returns all python types for which transformers are available

get_transformer()

def get_transformer(
    python_type: Type,
):

Implements a recursive search for the transformer.

guess_python_type()

def guess_python_type(
    flyte_type: LiteralType,
):

Transforms a flyte-specific LiteralType to a regular python value.

guess_python_types()

def guess_python_types(
    flyte_variable_dict: typing.Dict[str, _interface_models.Variable],
):

Transforms a dictionary of flyte-specific Variable objects to a dictionary of regular python values.

lazy_import_transformers()

def lazy_import_transformers()

Only load the transformers if needed.

literal_map_to_kwargs()

def literal_map_to_kwargs(
    ctx: FlyteContext,
    lm: LiteralMap,
    python_types: typing.Optional[typing.Dict[str, type]],
    literal_types: typing.Optional[typing.Dict[str, _interface_models.Variable]],
):

named_tuple_to_variable_map()

def named_tuple_to_variable_map(
    t: typing.NamedTuple,
):

Converts a python-native NamedTuple to a flyte-specific VariableMap of named literals.

register()

def register(
    transformer: TypeTransformer,
    additional_types: Optional[typing.List[Type]],
):

This should be used for all types that respond with the right type annotation when you use type(…) function

register_additional_type()

def register_additional_type(
    transformer: TypeTransformer[T],
    additional_type: Type[T],
    override,
):

register_restricted_type()

def register_restricted_type(
    name: str,
    type: Type[T],
):

to_html()

def to_html(
    ctx: FlyteContext,
    python_val: typing.Any,
    expected_python_type: Type[typing.Any],
):

to_literal()

def to_literal(
    ctx: FlyteContext,
    python_val: typing.Any,
    python_type: Type[T],
    expected: LiteralType,
):

The current dance is because we are allowing users to call from an async function, this synchronous to_literal function, and allowing this to_literal function, to then invoke yet another async function, namely an async transformer.

to_literal_checks()

def to_literal_checks(
    python_val: typing.Any,
    python_type: Type[T],
    expected: LiteralType,
):

to_literal_type()

def to_literal_type(
    python_type: Type[T],
):

Converts a python type into a flyte specific LiteralType

to_python_value()

def to_python_value(
    ctx: FlyteContext,
    lv: Literal,
    expected_python_type: Type,
):

Converts a Literal value with an expected python type into a python value.

unwrap_offloaded_literal()

def unwrap_offloaded_literal(
    ctx: FlyteContext,
    lv: Literal,
):

flytekit.core.base_task.TypeTransformerFailedError

Inappropriate argument type.

flytekit.core.base_task.TypeVar

Type variable.

The preferred way to construct a type variable is via the dedicated syntax for generic functions, classes, and type aliases::

class Sequence[T]: # T is a TypeVar …

This syntax can also be used to create bound and constrained type variables::

S is a TypeVar bound to str

class StrSequence[S: str]: …

A is a TypeVar constrained to str or bytes

class StrOrBytesSequence[A: (str, bytes)]: …

However, if desired, reusable type variables can also be constructed manually, like so::

T = TypeVar(‘T’) # Can be anything S = TypeVar(‘S’, bound=str) # Can be any subtype of str A = TypeVar(‘A’, str, bytes) # Must be exactly str or bytes

Type variables exist primarily for the benefit of static type checkers. They serve as the parameters for generic types as well as for generic function and type alias definitions.

The variance of type variables is inferred by type checkers when they are created through the type parameter syntax and when infer_variance=True is passed. Manually created type variables may be explicitly marked covariant or contravariant by passing covariant=True or contravariant=True. By default, manually created type variables are invariant. See PEP 484 and PEP 695 for more details.

flytekit.core.base_task.Variable

def Variable(
    type,
    description,
    artifact_partial_id: typing.Optional[flyteidl.core.artifact_id_pb2.ArtifactID],
    artifact_tag: typing.Optional[flyteidl.core.artifact_id_pb2.ArtifactTag],
):

Methods

from_flyte_idl()

def from_flyte_idl(
    variable_proto,
):

serialize_to_string()

def serialize_to_string()

short_string()

def short_string()

to_flyte_idl()

def to_flyte_idl()

to_flyte_idl_list()

def to_flyte_idl_list()

verbose_string()

def verbose_string()

Properties

flytekit.core.base_task.VoidPromise

This object is returned for tasks that do not return any outputs (declared interface is empty) VoidPromise cannot be interacted with and does not allow comparisons or any operations

def VoidPromise(
    task_name: str,
    ref: Optional[NodeOutput],
):

Methods

runs_before()

def runs_before(
    args,
    kwargs,
):

This is a placeholder and should do nothing. It is only here to enable local execution of workflows where a task returns nothing.

with_overrides()

def with_overrides(
    args,
    kwargs,
):

Properties

flytekit.core.base_task.timeit

A context manager and a decorator that measures the execution time of the wrapped code block or functions. It will append a timing information to TimeLineDeck. For instance:

@timeit(“Function description”) def function()

with timeit(“Wrapped code block description”):

your code

def timeit(
    name: str,
):