espnet2.iterators.abs_iter_factory.AbsIterFactory

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class espnet2.iterators.abs_iter_factory.AbsIterFactory

Bases: ABC

Abstract base class for iterator factories in the ESPnet2 framework.

This class defines a blueprint for creating iterators, which can be used to iterate over datasets in a structured manner. Concrete implementations of this class must provide an implementation for the build_iter method, which is responsible for constructing the iterator based on the specified epoch and shuffle parameters.

None

• Parameters:
  • epoch (int) – The current epoch number. This can be used to control the behavior of the iterator (e.g., shuffling).
  • shuffle (bool , optional) – A flag indicating whether to shuffle the data before iteration. Defaults to None.
• Returns: An iterator object that yields data items.
• Return type: Iterator
• Raises:NotImplementedError – If the build_iter method is not implemented by a subclass.

####### Examples

To create a custom iterator factory, subclass AbsIterFactory and implement the build_iter method:

``

`

python class CustomIterFactory(AbsIterFactory):

def build_iter(self, epoch: int, shuffle: bool = False) -> Iterator: : # Custom iterator logic goes here …

``

`

NOTE

This class is part of the ESPnet2 library and is intended for internal use within the framework.

abstract build_iter(epoch: int, shuffle: bool | None = None) → Iterator

Builds an iterator for the specified epoch.

This method is responsible for creating an iterator that can be used to traverse through the data for a given epoch. The iterator can be shuffled based on the provided parameter.

• Parameters:
  • epoch (int) – The epoch number for which the iterator is being built.
  • shuffle (bool , optional) – Whether to shuffle the data. Defaults to None.
• Returns: An iterator that allows iteration over the data for the specified epoch.
• Return type: Iterator
• Raises:NotImplementedError – If this method is not implemented in a subclass.

####### Examples

class MyIterFactory(AbsIterFactory): : def build_iter(self, epoch: int, shuffle: bool = False) -> Iterator: : # Implementation of iterator building logic here pass

factory = MyIterFactory() iterator = factory.build_iter(epoch=1, shuffle=True) for item in iterator:

print(item)

NOTE

The shuffle parameter’s default value should be explicitly handled in the implementation to ensure consistent behavior.