def __post_init__()

in pytorchvideo/data/utils.py [0:0]

• 20 lines of code
• 8 McCabe index (conditional complexity)

    def __post_init__(self) -> None:
        f"""
        This function is run by the dataclass library after '__init__'.

        Here we use this to ensure all fields are casted to their declared types
        and to apply any complex field_initializer functions that have been
        declared via the 'complex_initialized_dataclass_field' method of
        this class.

        A complex field_initializer for a given field would be stored in the
        field.metadata dictionary at:
            key = '{self.COMPLEX_INITIALIZER}' (self.COMPLEX_INITIALIZER)

        """
        for field in dataclass_fields(self):
            value = getattr(self, field.name)
            # First check if the datafield has been set to the declared type or
            # if the datafield has a declared complex field_initializer.
            if (
                not isinstance(value, field.type)
                or DataclassFieldCaster.COMPLEX_INITIALIZER in field.metadata
            ):
                # Apply the complex field_initializer function for this field's value,
                # assert that the resultant type is the declared type of the field.
                if DataclassFieldCaster.COMPLEX_INITIALIZER in field.metadata:
                    setattr(
                        self,
                        field.name,
                        field.metadata[DataclassFieldCaster.COMPLEX_INITIALIZER](value),
                    )
                    assert isinstance(getattr(self, field.name), field.type), (
                        f"'field_initializer' function of {field.name} must return "
                        f"type {field.type} but returned type {type(getattr(self, field.name))}"
                    )
                else:
                    # Otherwise attempt to cast the field's value to its declared type.
                    setattr(self, field.name, field.type(value))