Feature: multiple image loader function for extended folder structure in image classification

[sparkingdark]

Some image classification dataset has the following data structure:

--root
        |__test
        |__train
        |__val

To deal with this kind of dataset I implemented a function which can return a hub transform object list in the format corresponding to test,train and val.

─    debo@debo-Lenovo-ideapad-130-15IKB    ~/Hub     feature/multiple_image_loader      
╰─ /usr/bin/python3 /home/debo/Hub/test.py
['test_set', 'training_set']
parsing image classification dataset: 100%|███████████████████████████████████████████████| 2/2 [00:00<00:00,  9.35it/s]
{'image': Image(shape=(None, None, None), dtype='uint8', max_shape=(500, 500, 3)), 'label': ClassLabel(shape=(), dtype='uint16', names=['cats', 'dogs'], num_classes=2)}
parsing image classification dataset: 100%|███████████████████████████████████████████████| 2/2 [00:00<00:00,  2.53it/s]
{'image': Image(shape=(None, None, None), dtype='uint8', max_shape=(768, 1050, 3)), 'label': ClassLabel(shape=(), dtype='uint16', names=['cats', 'dogs'], num_classes=2)}
[<hub.compute.transform.Transform object at 0x7f3b14c71b50>, <hub.compute.transform.Transform object at 0x7f3b14bf86a0>]

a sample output above.

To do:

• [] add tests
• [] Add exception handling and direct data upload feature to the hub.

[Work in Progress]

Need review and feedback @davidbuniat @McCrearyD

[verbose-void]

looks good! but could you please write some tests? just add a (very small custom) dummy_dataset in this folder: https://github.com/activeloopai/Hub/tree/master/hub/auto/tests/dummy_data/image_classification

you can use the other datasets in that folder as a reference. & you don't need to make a new test file, you can place your tests in here: https://github.com/activeloopai/Hub/blob/master/hub/auto/tests/test_image_classification.py

[sparkingdark]

@McCrearyD tests added can you check it.

[verbose-void]

looks awesome! note: your dummy_data was missing a subdirectory "root" (to conform to the other tests) & the naming of the dummy_data subdirectory was changed to be folder_class_sample.

i will merge to master when the tests finish running.