apache_beam.typehints.typecheck module¶
Runtime type checking support.
For internal use only; no backwards-compatibility guarantees.
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class
apache_beam.typehints.typecheck.
AbstractDoFnWrapper
(dofn)[source]¶ Bases:
apache_beam.transforms.core.DoFn
An abstract class to create wrapper around DoFn
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class
apache_beam.typehints.typecheck.
OutputCheckWrapperDoFn
(dofn, full_label)[source]¶ Bases:
apache_beam.typehints.typecheck.AbstractDoFnWrapper
A DoFn that verifies against common errors in the output type.
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class
apache_beam.typehints.typecheck.
TypeCheckWrapperDoFn
(dofn, type_hints, label=None)[source]¶ Bases:
apache_beam.typehints.typecheck.AbstractDoFnWrapper
A wrapper around a DoFn which performs type-checking of input and output.
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static
type_check
(type_constraint, datum, is_input)[source]¶ 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’.
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static
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class
apache_beam.typehints.typecheck.
TypeCheckCombineFn
(combinefn, type_hints, label=None)[source]¶ Bases:
apache_beam.transforms.core.CombineFn
A wrapper around a CombineFn performing type-checking of input and output.