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5 months ago
import os
from pathlib import Path
from typing import Any, Callable, List, Optional, Tuple, Union
import torch.utils.data as data
from ..utils import _log_api_usage_once
class VisionDataset(data.Dataset):
"""
Base Class For making datasets which are compatible with torchvision.
It is necessary to override the ``__getitem__`` and ``__len__`` method.
Args:
root (string, optional): Root directory of dataset. Only used for `__repr__`.
transforms (callable, optional): A function/transforms that takes in
an image and a label and returns the transformed versions of both.
transform (callable, optional): A function/transform that takes in a PIL image
and returns a transformed version. E.g, ``transforms.RandomCrop``
target_transform (callable, optional): A function/transform that takes in the
target and transforms it.
.. note::
:attr:`transforms` and the combination of :attr:`transform` and :attr:`target_transform` are mutually exclusive.
"""
_repr_indent = 4
def __init__(
self,
root: Union[str, Path] = None, # type: ignore[assignment]
transforms: Optional[Callable] = None,
transform: Optional[Callable] = None,
target_transform: Optional[Callable] = None,
) -> None:
_log_api_usage_once(self)
if isinstance(root, str):
root = os.path.expanduser(root)
self.root = root
has_transforms = transforms is not None
has_separate_transform = transform is not None or target_transform is not None
if has_transforms and has_separate_transform:
raise ValueError("Only transforms or transform/target_transform can be passed as argument")
# for backwards-compatibility
self.transform = transform
self.target_transform = target_transform
if has_separate_transform:
transforms = StandardTransform(transform, target_transform)
self.transforms = transforms
def __getitem__(self, index: int) -> Any:
"""
Args:
index (int): Index
Returns:
(Any): Sample and meta data, optionally transformed by the respective transforms.
"""
raise NotImplementedError
def __len__(self) -> int:
raise NotImplementedError
def __repr__(self) -> str:
head = "Dataset " + self.__class__.__name__
body = [f"Number of datapoints: {self.__len__()}"]
if self.root is not None:
body.append(f"Root location: {self.root}")
body += self.extra_repr().splitlines()
if hasattr(self, "transforms") and self.transforms is not None:
body += [repr(self.transforms)]
lines = [head] + [" " * self._repr_indent + line for line in body]
return "\n".join(lines)
def _format_transform_repr(self, transform: Callable, head: str) -> List[str]:
lines = transform.__repr__().splitlines()
return [f"{head}{lines[0]}"] + ["{}{}".format(" " * len(head), line) for line in lines[1:]]
def extra_repr(self) -> str:
return ""
class StandardTransform:
def __init__(self, transform: Optional[Callable] = None, target_transform: Optional[Callable] = None) -> None:
self.transform = transform
self.target_transform = target_transform
def __call__(self, input: Any, target: Any) -> Tuple[Any, Any]:
if self.transform is not None:
input = self.transform(input)
if self.target_transform is not None:
target = self.target_transform(target)
return input, target
def _format_transform_repr(self, transform: Callable, head: str) -> List[str]:
lines = transform.__repr__().splitlines()
return [f"{head}{lines[0]}"] + ["{}{}".format(" " * len(head), line) for line in lines[1:]]
def __repr__(self) -> str:
body = [self.__class__.__name__]
if self.transform is not None:
body += self._format_transform_repr(self.transform, "Transform: ")
if self.target_transform is not None:
body += self._format_transform_repr(self.target_transform, "Target transform: ")
return "\n".join(body)