apache_beam.typehints.typecheck module

Runtime type checking support.

For internal use only; no backwards-compatibility guarantees.

class apache_beam.typehints.typecheck.AbstractDoFnWrapper(dofn)

Bases: apache_beam.transforms.core.DoFn

An abstract class to create wrapper around DoFn

wrapper(method, args, kwargs)

setup()

start_bundle(*args, **kwargs)

process(*args, **kwargs)

finish_bundle(*args, **kwargs)

teardown()

BundleFinalizerParam

alias of apache_beam.transforms.core._BundleFinalizerParam

DoFnProcessParams = [ElementParam, SideInputParam, TimestampParam, WindowParam, <class 'apache_beam.transforms.core._WatermarkEstimatorParam'>, PaneInfoParam, <class 'apache_beam.transforms.core._BundleFinalizerParam'>, KeyParam, <class 'apache_beam.transforms.core._StateDoFnParam'>, <class 'apache_beam.transforms.core._TimerDoFnParam'>]

DynamicTimerTagParam = DynamicTimerTagParam

ElementParam = ElementParam

KeyParam = KeyParam

PaneInfoParam = PaneInfoParam

RestrictionParam

alias of apache_beam.transforms.core._RestrictionDoFnParam

SideInputParam = SideInputParam

StateParam

alias of apache_beam.transforms.core._StateDoFnParam

TimerParam

alias of apache_beam.transforms.core._TimerDoFnParam

TimestampParam = TimestampParam

WatermarkEstimatorParam

alias of apache_beam.transforms.core._WatermarkEstimatorParam

WindowParam = WindowParam

default_label()

default_type_hints()

display_data()

Returns the display data associated to a pipeline component.

It should be reimplemented in pipeline components that wish to have static display data.

Returns:A dictionary containing key:value pairs. The value might be an integer, float or string value; a DisplayDataItem for values that have more data (e.g. short value, label, url); or a HasDisplayData instance that has more display data that should be picked up. For example:

{
  'key1': 'string_value',
  'key2': 1234,
  'key3': 3.14159265,
  'key4': DisplayDataItem('apache.org', url='http://apache.org'),
  'key5': subComponent
}

Return type:Dict[str, Any]

static from_callable(fn)

classmethod from_runner_api(fn_proto, context)

Converts from an FunctionSpec to a Fn object.

Prefer registering a urn with its parameter type and constructor.

get_function_arguments(func)

get_type_hints()

Gets and/or initializes type hints for this object.

If type hints have not been set, attempts to initialize type hints in this order: - Using self.default_type_hints(). - Using self.__class__ type hints.

infer_output_type(input_type)

classmethod register_pickle_urn(pickle_urn)

Registers and implements the given urn via pickling.

classmethod register_urn(urn, parameter_type, fn=None)

Registers a urn with a constructor.

For example, if ‘beam:fn:foo’ had parameter type FooPayload, one could write RunnerApiFn.register_urn(‘bean:fn:foo’, FooPayload, foo_from_proto) where foo_from_proto took as arguments a FooPayload and a PipelineContext. This function can also be used as a decorator rather than passing the callable in as the final parameter.

A corresponding to_runner_api_parameter method would be expected that returns the tuple (‘beam:fn:foo’, FooPayload)

to_runner_api(context)

Returns an FunctionSpec encoding this Fn.

Prefer overriding self.to_runner_api_parameter.

to_runner_api_parameter(context)

static unbounded_per_element()

A decorator on process fn specifying that the fn performs an unbounded amount of work per input element.

with_input_types(*arg_hints, **kwarg_hints)

with_output_types(*arg_hints, **kwarg_hints)

class apache_beam.typehints.typecheck.OutputCheckWrapperDoFn(dofn, full_label)

Bases: apache_beam.typehints.typecheck.AbstractDoFnWrapper

A DoFn that verifies against common errors in the output type.

wrapper(method, args, kwargs)

BundleFinalizerParam

alias of apache_beam.transforms.core._BundleFinalizerParam

DoFnProcessParams = [ElementParam, SideInputParam, TimestampParam, WindowParam, <class 'apache_beam.transforms.core._WatermarkEstimatorParam'>, PaneInfoParam, <class 'apache_beam.transforms.core._BundleFinalizerParam'>, KeyParam, <class 'apache_beam.transforms.core._StateDoFnParam'>, <class 'apache_beam.transforms.core._TimerDoFnParam'>]

DynamicTimerTagParam = DynamicTimerTagParam

ElementParam = ElementParam

KeyParam = KeyParam

PaneInfoParam = PaneInfoParam

RestrictionParam

alias of apache_beam.transforms.core._RestrictionDoFnParam

SideInputParam = SideInputParam

StateParam

alias of apache_beam.transforms.core._StateDoFnParam

TimerParam

alias of apache_beam.transforms.core._TimerDoFnParam

TimestampParam = TimestampParam

WatermarkEstimatorParam

alias of apache_beam.transforms.core._WatermarkEstimatorParam

WindowParam = WindowParam

default_label()

default_type_hints()

display_data()

Returns the display data associated to a pipeline component.

It should be reimplemented in pipeline components that wish to have static display data.

Returns:A dictionary containing key:value pairs. The value might be an integer, float or string value; a DisplayDataItem for values that have more data (e.g. short value, label, url); or a HasDisplayData instance that has more display data that should be picked up. For example:

{
  'key1': 'string_value',
  'key2': 1234,
  'key3': 3.14159265,
  'key4': DisplayDataItem('apache.org', url='http://apache.org'),
  'key5': subComponent
}

Return type:Dict[str, Any]

finish_bundle(*args, **kwargs)

static from_callable(fn)

classmethod from_runner_api(fn_proto, context)

Converts from an FunctionSpec to a Fn object.

Prefer registering a urn with its parameter type and constructor.

get_function_arguments(func)

get_type_hints()

Gets and/or initializes type hints for this object.

If type hints have not been set, attempts to initialize type hints in this order: - Using self.default_type_hints(). - Using self.__class__ type hints.

infer_output_type(input_type)

process(*args, **kwargs)

classmethod register_pickle_urn(pickle_urn)

Registers and implements the given urn via pickling.

classmethod register_urn(urn, parameter_type, fn=None)

Registers a urn with a constructor.

For example, if ‘beam:fn:foo’ had parameter type FooPayload, one could write RunnerApiFn.register_urn(‘bean:fn:foo’, FooPayload, foo_from_proto) where foo_from_proto took as arguments a FooPayload and a PipelineContext. This function can also be used as a decorator rather than passing the callable in as the final parameter.

A corresponding to_runner_api_parameter method would be expected that returns the tuple (‘beam:fn:foo’, FooPayload)

setup()

start_bundle(*args, **kwargs)

teardown()

to_runner_api(context)

Returns an FunctionSpec encoding this Fn.

Prefer overriding self.to_runner_api_parameter.

to_runner_api_parameter(context)

static unbounded_per_element()

A decorator on process fn specifying that the fn performs an unbounded amount of work per input element.

with_input_types(*arg_hints, **kwarg_hints)

with_output_types(*arg_hints, **kwarg_hints)

class apache_beam.typehints.typecheck.TypeCheckWrapperDoFn(dofn, type_hints, label=None)

Bases: apache_beam.typehints.typecheck.AbstractDoFnWrapper

A wrapper around a DoFn which performs type-checking of input and output.

wrapper(method, args, kwargs)

process(*args, **kwargs)

static type_check(type_constraint, datum, is_input)

Typecheck a PTransform related datum according to a type constraint.

This function is used to optionally type-check either an input or an output to a PTransform.

Parameters:

• type_constraint – An instance of a typehints.TypeContraint, one of the white-listed builtin Python types, or a custom user class.
• datum – An instance of a Python object.
• is_input – True if ‘datum’ is an input to a PTransform’s DoFn. False otherwise.

Raises:

TypeError – If ‘datum’ fails to type-check according to ‘type_constraint’.

BundleFinalizerParam

alias of apache_beam.transforms.core._BundleFinalizerParam

DoFnProcessParams = [ElementParam, SideInputParam, TimestampParam, WindowParam, <class 'apache_beam.transforms.core._WatermarkEstimatorParam'>, PaneInfoParam, <class 'apache_beam.transforms.core._BundleFinalizerParam'>, KeyParam, <class 'apache_beam.transforms.core._StateDoFnParam'>, <class 'apache_beam.transforms.core._TimerDoFnParam'>]

DynamicTimerTagParam = DynamicTimerTagParam

ElementParam = ElementParam

KeyParam = KeyParam

PaneInfoParam = PaneInfoParam

RestrictionParam

alias of apache_beam.transforms.core._RestrictionDoFnParam

SideInputParam = SideInputParam

StateParam

alias of apache_beam.transforms.core._StateDoFnParam

TimerParam

alias of apache_beam.transforms.core._TimerDoFnParam

TimestampParam = TimestampParam

WatermarkEstimatorParam

alias of apache_beam.transforms.core._WatermarkEstimatorParam

WindowParam = WindowParam

default_label()

default_type_hints()

display_data()

Returns the display data associated to a pipeline component.

It should be reimplemented in pipeline components that wish to have static display data.

Returns:A dictionary containing key:value pairs. The value might be an integer, float or string value; a DisplayDataItem for values that have more data (e.g. short value, label, url); or a HasDisplayData instance that has more display data that should be picked up. For example:

{
  'key1': 'string_value',
  'key2': 1234,
  'key3': 3.14159265,
  'key4': DisplayDataItem('apache.org', url='http://apache.org'),
  'key5': subComponent
}

Return type:Dict[str, Any]

finish_bundle(*args, **kwargs)

static from_callable(fn)

classmethod from_runner_api(fn_proto, context)

Converts from an FunctionSpec to a Fn object.

Prefer registering a urn with its parameter type and constructor.

get_function_arguments(func)

get_type_hints()

Gets and/or initializes type hints for this object.

If type hints have not been set, attempts to initialize type hints in this order: - Using self.default_type_hints(). - Using self.__class__ type hints.

infer_output_type(input_type)

classmethod register_pickle_urn(pickle_urn)

Registers and implements the given urn via pickling.

classmethod register_urn(urn, parameter_type, fn=None)

Registers a urn with a constructor.

For example, if ‘beam:fn:foo’ had parameter type FooPayload, one could write RunnerApiFn.register_urn(‘bean:fn:foo’, FooPayload, foo_from_proto) where foo_from_proto took as arguments a FooPayload and a PipelineContext. This function can also be used as a decorator rather than passing the callable in as the final parameter.

A corresponding to_runner_api_parameter method would be expected that returns the tuple (‘beam:fn:foo’, FooPayload)

setup()

start_bundle(*args, **kwargs)

teardown()

to_runner_api(context)

Returns an FunctionSpec encoding this Fn.

Prefer overriding self.to_runner_api_parameter.

to_runner_api_parameter(context)

static unbounded_per_element()

A decorator on process fn specifying that the fn performs an unbounded amount of work per input element.

with_input_types(*arg_hints, **kwarg_hints)

with_output_types(*arg_hints, **kwarg_hints)

class apache_beam.typehints.typecheck.TypeCheckCombineFn(combinefn, type_hints, label=None)

Bases: apache_beam.transforms.core.CombineFn

A wrapper around a CombineFn performing type-checking of input and output.

setup(*args, **kwargs)

create_accumulator(*args, **kwargs)

add_input(accumulator, element, *args, **kwargs)

merge_accumulators(accumulators, *args, **kwargs)

compact(accumulator, *args, **kwargs)

extract_output(accumulator, *args, **kwargs)

teardown(*args, **kwargs)

add_inputs(mutable_accumulator, elements, *args, **kwargs)

Returns the result of folding each element in elements into accumulator.

This is provided in case the implementation affords more efficient bulk addition of elements. The default implementation simply loops over the inputs invoking add_input for each one.

Parameters:

• mutable_accumulator – the current accumulator, may be modified and returned for efficiency
• elements – the elements to add, should not be mutated
• *args – Additional arguments and side inputs.
• **kwargs – Additional arguments and side inputs.

apply(elements, *args, **kwargs)

Returns result of applying this CombineFn to the input values.

Parameters:

• elements – the set of values to combine.
• *args – Additional arguments and side inputs.
• **kwargs – Additional arguments and side inputs.

default_label()

default_type_hints()

display_data()

Returns the display data associated to a pipeline component.

It should be reimplemented in pipeline components that wish to have static display data.

Returns:A dictionary containing key:value pairs. The value might be an integer, float or string value; a DisplayDataItem for values that have more data (e.g. short value, label, url); or a HasDisplayData instance that has more display data that should be picked up. For example:

{
  'key1': 'string_value',
  'key2': 1234,
  'key3': 3.14159265,
  'key4': DisplayDataItem('apache.org', url='http://apache.org'),
  'key5': subComponent
}

Return type:Dict[str, Any]

for_input_type(input_type)

Returns a specialized implementation of self, if it exists.

Otherwise, returns self.

Parameters:input_type – the type of input elements.

static from_callable(fn)

classmethod from_runner_api(fn_proto, context)

Converts from an FunctionSpec to a Fn object.

Prefer registering a urn with its parameter type and constructor.

get_accumulator_coder()

get_type_hints()

Gets and/or initializes type hints for this object.

If type hints have not been set, attempts to initialize type hints in this order: - Using self.default_type_hints(). - Using self.__class__ type hints.

static maybe_from_callable(fn, has_side_inputs=True)

classmethod register_pickle_urn(pickle_urn)

Registers and implements the given urn via pickling.

classmethod register_urn(urn, parameter_type, fn=None)

Registers a urn with a constructor.

For example, if ‘beam:fn:foo’ had parameter type FooPayload, one could write RunnerApiFn.register_urn(‘bean:fn:foo’, FooPayload, foo_from_proto) where foo_from_proto took as arguments a FooPayload and a PipelineContext. This function can also be used as a decorator rather than passing the callable in as the final parameter.

A corresponding to_runner_api_parameter method would be expected that returns the tuple (‘beam:fn:foo’, FooPayload)

to_runner_api(context)

Returns an FunctionSpec encoding this Fn.

Prefer overriding self.to_runner_api_parameter.

to_runner_api_parameter(context)

with_input_types(*arg_hints, **kwarg_hints)

with_output_types(*arg_hints, **kwarg_hints)

class apache_beam.typehints.typecheck.TypeCheckVisitor

Bases: apache_beam.pipeline.PipelineVisitor

enter_composite_transform(applied_transform)

leave_composite_transform(applied_transform)

visit_transform(applied_transform)

visit_value(value, producer_node)

Callback for visiting a PValue in the pipeline DAG.

Parameters:

• value – PValue visited (typically a PCollection instance).
• producer_node – AppliedPTransform object whose transform produced the pvalue.

class apache_beam.typehints.typecheck.PerformanceTypeCheckVisitor

Bases: apache_beam.pipeline.PipelineVisitor

visit_transform(applied_transform)

get_input_type_hints(transform)

enter_composite_transform(transform_node)

Callback for entering traversal of a composite transform node.

get_output_type_hints(transform)

leave_composite_transform(transform_node)

Callback for leaving traversal of a composite transform node.

visit_value(value, producer_node)

Callback for visiting a PValue in the pipeline DAG.

Parameters:

• value – PValue visited (typically a PCollection instance).
• producer_node – AppliedPTransform object whose transform produced the pvalue.