num_workers = 0 if sys.platform.startswith('win32') else 4 train_iter = gdata.DataLoader( gb.VOCSegDataset(True, crop_size, voc_dir, colormap2label), batch_size, shuffle=True, last_batch='discard', num_workers=num_workers) shuffle=True, last_batch='discard', num_workers=4) test_...