fastai.dataloader

Introduction and Overview

Note

the fastai DataLoader has a similar API to the PyTorch DataLoader. Please see .. the PyTorch documentation: http://pytorch.org/docs/master/data.html#torch.utils.data.DataLoader for usage and details. The documentation presented here focuses on the differences between the two classes.

Class DataLoader

class fastai.dataloader.DataLoader(dataset, batch_size=1, shuffle=False, sampler=None, batch_sampler=None, pad_idx=0, num_workers=None, pin_memory=False, drop_last=False, pre_pad=True, half=False, transpose=False, transpose_y=False)

Methods

{{method jag_stack,b}}

Helper method for np_collate(). Returns a np.array of the batch passed in, with zeros added for any shorter rows inside the batch, plus extra zeros if self.pad_idx > 0. If all items inside the batch are the same length, no zero padding is added.

{{method np_collate,batch}}

Helper method for get_batch(). Based on the input data type, it creates an appropriate np.array, list, or dict. If the method is passed a string or list of strings, it simply returns the parameter without modification. Batches must contain numbers, strings, dicts, or lists, and this method also ensures this is the case.

{{method get_batch,indices}}

Helper method for __iter__(). When an iterator of the dataloader object is created, get_batch() is used to retrieve items from the dataset and apply transposes if needed based on self.transpose and self.transpose_y.