File size: 33,883 Bytes
639f152
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4599473
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
639f152
 
 
 
 
 
 
 
 
4599473
 
 
 
 
 
639f152
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
26af90a
639f152
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
26af90a
639f152
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
26af90a
639f152
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4599473
 
 
 
 
 
639f152
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
---
license: mit
viewer: false
task_categories:
- image-classification
task_ids:
- multi-class-image-classification
tags:
- computer-vision
- product-classification
- e-commerce
- retail
- few-shot-learning
- meta-learning
- benchmark
size_categories:
- 100K<n<1M
language:
- en
pretty_name: FSL Product Classification Dataset
configs:
- config_name: default
  data_files: "data.tzst"
  default: true
dataset_info:
  features:
  - name: image
    dtype: image
  - name: label
    dtype: int64
  - name: class_name
    dtype: string
  - name: image_id
    dtype: string
  splits:
  - name: train
    num_bytes: 9945644054
    num_examples: 279747
  download_size: 9945644054
  dataset_size: 9945644054
---

# Few-Shot Learning (FSL) Product Classification Dataset

## Dataset Description

This dataset is designed for **Few-Shot Learning (FSL)** research in product classification tasks. It contains product images organized into 763 distinct classes, with an average of approximately 367 images per class (279,747 total images), making it ideal for training and evaluating few-shot learning algorithms in e-commerce and retail scenarios. Note that class numbers are not continuous.

### Key Features

- **763 product classes** covering diverse product categories
- **279,747 total images** (average of ~367 images per class)
- **High-quality product images** suitable for computer vision research
- **Variable class distribution** with non-continuous class numbers
- **Efficient tzst compression** for reduced storage and faster transfer

### Dataset Statistics

- **Total Classes**: 763
- **Total Images**: 279,747
- **Images per Class**: ~367 (average, variable distribution)
- **Class Numbers**: Non-continuous (some class numbers may be missing)
- **Image Format**: PNG
- **Typical Image Size**: 50-100 KB per image
- **Compressed Archive Size**: ~9.9 GB (data.tzst)

## Dataset Structure

The dataset is stored in a compressed tzst archive ([`data.tzst`](data.tzst)) with the following structure:

```text
data.tzst
├── class_0/
│   ├── class_0_0.png
│   ├── class_0_1.png
│   └── ...
├── class_1/
│   ├── class_1_0.png
│   ├── class_1_1.png
│   └── ...
└── ... (763 total classes with non-continuous numbers)
```

**Note**: Class numbers are not continuous. For example, you might have class_0, class_2, class_5, etc., but not class_1, class_3, class_4. The total number of classes is 763.

## Quick Start

Get started with the FSL Product Classification dataset in just a few steps:

```python
from datasets import Dataset
import os
from tzst import extract_archive

# 1. Extract the dataset
extract_archive("data.tzst", "extracted_data/")

# 2. Load a few samples
data_dir = "extracted_data"
samples = []
for class_dir in sorted(os.listdir(data_dir))[:3]:  # First 3 classes
    if class_dir.startswith("class_"):
        class_path = os.path.join(data_dir, class_dir)
        for img_file in os.listdir(class_path)[:5]:  # First 5 images
            if img_file.endswith('.png'):
                samples.append({
                    'image': os.path.join(class_path, img_file),
                    'label': int(class_dir.split("_")[1]),
                    'class_name': class_dir,
                    'image_id': img_file.replace('.png', '')
                })

print(f"Loaded {len(samples)} sample images from 3 classes")
```

For complete setup and advanced usage, see the sections below.

## Usage

## Installation and Setup

### Quick Start Installation

```bash
# Create a new virtual environment (recommended)
python -m venv fsl-env

# Activate virtual environment
# On Windows:
fsl-env\Scripts\activate
# On macOS/Linux:
# source fsl-env/bin/activate

# Install core dependencies
pip install datasets tzst pillow

# Install additional dependencies for machine learning
pip install torch torchvision numpy scikit-learn matplotlib seaborn tqdm

# For Jupyter notebook users
pip install jupyter ipywidgets
```

### Complete Requirements

Create a `requirements.txt` file with the following dependencies:

```text
# Core dependencies
datasets>=2.14.0
tzst>=1.2.8
pillow>=9.0.0

# Machine learning
torch>=1.9.0
torchvision>=0.10.0
numpy>=1.21.0
scikit-learn>=1.0.0

# Data analysis and visualization
pandas>=1.3.0
matplotlib>=3.4.0
seaborn>=0.11.0

# Progress bars and utilities
tqdm>=4.62.0
pathlib>=1.0.1

# Optional: for advanced few-shot learning
learn2learn>=0.1.7
higher>=0.2.1

# Optional: for notebook usage
jupyter>=1.0.0
ipywidgets>=7.6.0
```

Install all requirements:

```bash
pip install -r requirements.txt
```

### Docker Setup (Optional)

For a containerized environment:

```dockerfile
FROM python:3.9-slim

WORKDIR /app

# Install system dependencies
RUN apt-get update && apt-get install -y \
    git \
    wget \
    && rm -rf /var/lib/apt/lists/*

# Copy requirements and install Python dependencies
COPY requirements.txt .
RUN pip install --no-cache-dir -r requirements.txt

# Copy application code
COPY . .

# Set environment variables
ENV PYTHONPATH=/app
ENV HF_DATASETS_CACHE=/app/cache

# Create cache directory
RUN mkdir -p /app/cache

CMD ["python", "-c", "print('FSL Product Classification environment ready!')"]
```

Build and run:

```bash
docker build -t fsl-product-classification .
docker run -it --rm -v $(pwd)/data:/app/data fsl-product-classification bash
```

### Loading the Dataset

```python
import os
from tzst import extract_archive
from datasets import Dataset, Features, Value, Image, ClassLabel
from PIL import Image as PILImage

# Extract the dataset archive
extract_archive("data.tzst", "extracted_data/")

# Create a custom dataset loader
def load_fsl_dataset(data_dir="extracted_data"):
    samples = []
    class_names = []
    
    # Scan for class directories
    for class_dir in sorted(os.listdir(data_dir)):
        if class_dir.startswith("class_"):
            class_path = os.path.join(data_dir, class_dir)
            if os.path.isdir(class_path):
                class_id = int(class_dir.split("_")[1])
                class_names.append(class_dir)
                
                # Load images from this class
                for img_file in os.listdir(class_path):
                    if img_file.endswith('.png'):
                        img_path = os.path.join(class_path, img_file)
                        image_id = img_file.replace('.png', '')
                        
                        samples.append({
                            'image': img_path,
                            'label': class_id,
                            'class_name': class_dir,
                            'image_id': image_id
                        })
    
    # Create features definition
    features = Features({
        'image': Image(),
        'label': Value('int64'),
        'class_name': Value('string'),
        'image_id': Value('string')
    })
    
    # Create dataset
    return Dataset.from_list(samples, features=features)

# Load the dataset
dataset = load_fsl_dataset()
print(f"Loaded {len(dataset)} samples from {len(set(dataset['class_name']))} classes")
```

Streaming mode for memory-efficient processing of large archive:

```python
from tzst import extract_archive
import tempfile
import os

# Use streaming extraction for memory efficiency
with tempfile.TemporaryDirectory() as temp_dir:
    # Extract with streaming mode
    extract_archive("data.tzst", temp_dir, streaming=True)
    
    # Process extracted data
    dataset = load_fsl_dataset(temp_dir)
    # ... your processing code here
```

### Data Exploration

```python
from collections import Counter
import matplotlib.pyplot as plt

# Analyze class distribution
class_counts = Counter(dataset['class_name'])
print(f"Number of classes: {len(class_counts)}")
print(f"Average images per class: {len(dataset) / len(class_counts):.1f}")

# Plot class distribution (top 20 classes)
top_classes = class_counts.most_common(20)
classes, counts = zip(*top_classes)

plt.figure(figsize=(12, 6))
plt.bar(range(len(classes)), counts)
plt.xlabel('Class')
plt.ylabel('Number of Images')
plt.title('Top 20 Classes by Image Count')
plt.xticks(range(len(classes)), [c.replace('class_', '') for c in classes], rotation=45)
plt.tight_layout()
plt.show()

# Display sample images
import random

def show_samples(dataset, num_samples=8):
    """Display random samples from the dataset"""
    indices = random.sample(range(len(dataset)), num_samples)
    
    fig, axes = plt.subplots(2, 4, figsize=(15, 8))
    axes = axes.flatten()
    
    for i, idx in enumerate(indices):
        sample = dataset[idx]
        axes[i].imshow(sample['image'])
        axes[i].set_title(f"{sample['class_name']}\nID: {sample['image_id']}")
        axes[i].axis('off')
    
    plt.tight_layout()
    plt.show()

# Show sample images
show_samples(dataset)
```

### Few-Shot Learning Setup

#### Basic Few-Shot Episode Creation

```python
import random
from collections import defaultdict
import torch
from torch.utils.data import DataLoader

def create_few_shot_split(dataset, n_way=5, k_shot=5, n_query=15, seed=None):
    """
    Create a few-shot learning episode
    
    Args:
        dataset: Hugging Face Dataset instance or custom dataset
        n_way: Number of classes in the episode
        k_shot: Number of support samples per class
        n_query: Number of query samples per class
        seed: Random seed for reproducibility
    
    Returns:
        support_set, query_set: Lists of (image, label) tuples
    """
    if seed is not None:
        random.seed(seed)
    
    # Group samples by class
    class_samples = defaultdict(list)
    for i, sample in enumerate(dataset):
        class_samples[sample['label']].append(i)
    
    # Filter classes with enough samples
    valid_classes = [
        class_id for class_id, indices in class_samples.items() 
        if len(indices) >= k_shot + n_query
    ]
    
    if len(valid_classes) < n_way:
        raise ValueError(f"Not enough classes with {k_shot + n_query} samples. "
                        f"Found {len(valid_classes)}, need {n_way}")
    
    # Sample n_way classes
    episode_classes = random.sample(valid_classes, n_way)
    
    support_set = []
    query_set = []
    
    for new_label, original_class in enumerate(episode_classes):
        class_indices = random.sample(class_samples[original_class], k_shot + n_query)
        
        # Support samples
        for idx in class_indices[:k_shot]:
            sample = dataset[idx]
            support_set.append((sample['image'], new_label, sample['image_id']))
        
        # Query samples
        for idx in class_indices[k_shot:]:
            sample = dataset[idx]
            query_set.append((sample['image'], new_label, sample['image_id']))
    
    return support_set, query_set

# Create a 5-way 5-shot episode
support_set, query_set = create_few_shot_split(dataset, n_way=5, k_shot=5, n_query=15)

print(f"Support set: {len(support_set)} samples")
print(f"Query set: {len(query_set)} samples")
```

#### Advanced FSL Dataset Class

```python
import torch
from torch.utils.data import Dataset
from torchvision import transforms
from PIL import Image
import numpy as np

class FSLProductDataset(Dataset):
    """
    Few-Shot Learning Dataset wrapper for product classification
    """
    
    def __init__(self, hf_dataset, transform=None, target_transform=None):
        self.dataset = hf_dataset
        self.transform = transform or self.get_default_transform()
        self.target_transform = target_transform
        
        # Create label mapping for non-continuous labels
        unique_labels = sorted(set(hf_dataset['label']))
        self.label_to_idx = {label: idx for idx, label in enumerate(unique_labels)}
        self.idx_to_label = {idx: label for label, idx in self.label_to_idx.items()}
        
    def get_default_transform(self):
        """Default image transformations"""
        return transforms.Compose([
            transforms.Resize((224, 224)),
            transforms.ToTensor(),
            transforms.Normalize(mean=[0.485, 0.456, 0.406], 
                               std=[0.229, 0.224, 0.225])
        ])
    
    def __len__(self):
        return len(self.dataset)
    
    def __getitem__(self, idx):
        sample = self.dataset[idx]
        image = sample['image']
        
        # Convert to PIL Image if needed
        if not isinstance(image, Image.Image):
            image = Image.fromarray(image)
        
        # Apply transforms
        if self.transform:
            image = self.transform(image)
            
        # Map label to continuous indices
        label = self.label_to_idx[sample['label']]
        
        if self.target_transform:
            label = self.target_transform(label)
            
        return image, label, sample['image_id']
    
    def get_class_samples(self, class_label):
        """Get all samples for a specific class"""
        indices = [i for i, sample in enumerate(self.dataset) 
                  if sample['label'] == class_label]
        return [self[i] for i in indices]
    
    def create_episode_dataloader(self, n_way=5, k_shot=5, n_query=15, 
                                 batch_size=None, shuffle=True):
        """Create a DataLoader for a few-shot episode"""
        support_set, query_set = create_few_shot_split(
            self.dataset, n_way=n_way, k_shot=k_shot, n_query=n_query
        )
        
        # Convert to tensors
        support_images = []
        support_labels = []
        query_images = []
        query_labels = []
        
        for image, label, _ in support_set:
            if isinstance(image, Image.Image):
                image = self.transform(image) if self.transform else image
            support_images.append(image)
            support_labels.append(label)
            
        for image, label, _ in query_set:
            if isinstance(image, Image.Image):
                image = self.transform(image) if self.transform else image
            query_images.append(image)
            query_labels.append(label)
        
        support_data = (torch.stack(support_images), torch.tensor(support_labels))
        query_data = (torch.stack(query_images), torch.tensor(query_labels))
        
        return support_data, query_data

# Example usage with PyTorch
transform = transforms.Compose([
    transforms.Resize((84, 84)),  # Common size for few-shot learning
    transforms.ToTensor(),
    transforms.Normalize(mean=[0.485, 0.456, 0.406], 
                        std=[0.229, 0.224, 0.225])
])

# Load dataset
fsl_dataset = FSLProductDataset(dataset, transform=transform)

# Create episode data
support_data, query_data = fsl_dataset.create_episode_dataloader(
    n_way=5, k_shot=1, n_query=15
)

print(f"Support images shape: {support_data[0].shape}")
print(f"Support labels shape: {support_data[1].shape}")
print(f"Query images shape: {query_data[0].shape}")
print(f"Query labels shape: {query_data[1].shape}")
```

#### Meta-Learning Training Loop

```python
import torch.nn as nn
import torch.optim as optim
from tqdm import tqdm

def train_fsl_model(model, dataset, num_episodes=1000, n_way=5, k_shot=1, 
                   n_query=15, lr=0.001, device='cuda'):
    """
    Basic training loop for few-shot learning
    
    Args:
        model: Few-shot learning model (e.g., Prototypical Network)
        dataset: FSLProductDataset instance
        num_episodes: Number of training episodes
        n_way, k_shot, n_query: Episode configuration
        lr: Learning rate
        device: Training device
    """
    model.to(device)
    optimizer = optim.Adam(model.parameters(), lr=lr)
    criterion = nn.CrossEntropyLoss()
    
    model.train()
    total_loss = 0
    total_acc = 0
    
    for episode in tqdm(range(num_episodes), desc="Training"):
        # Create episode
        support_data, query_data = dataset.create_episode_dataloader(
            n_way=n_way, k_shot=k_shot, n_query=n_query
        )
        
        support_images, support_labels = support_data
        query_images, query_labels = query_data
        
        # Move to device
        support_images = support_images.to(device)
        support_labels = support_labels.to(device)
        query_images = query_images.to(device)
        query_labels = query_labels.to(device)
        
        # Forward pass
        optimizer.zero_grad()
        logits = model(support_images, support_labels, query_images)
        loss = criterion(logits, query_labels)
        
        # Backward pass
        loss.backward()
        optimizer.step()
        
        # Calculate accuracy
        pred = logits.argmax(dim=1)
        acc = (pred == query_labels).float().mean()
        
        total_loss += loss.item()
        total_acc += acc.item()
        
        if (episode + 1) % 100 == 0:
            avg_loss = total_loss / 100
            avg_acc = total_acc / 100
            print(f"Episode {episode + 1}: Loss = {avg_loss:.4f}, Acc = {avg_acc:.4f}")
            total_loss = 0
            total_acc = 0

# Example: Simple Prototypical Network
class SimplePrototypicalNetwork(nn.Module):
    def __init__(self, backbone):
        super().__init__()
        self.backbone = backbone
        
    def forward(self, support_images, support_labels, query_images):
        # Encode images
        support_features = self.backbone(support_images)
        query_features = self.backbone(query_images)
        
        # Calculate prototypes
        n_way = len(torch.unique(support_labels))
        prototypes = []
        
        for class_idx in range(n_way):
            class_mask = support_labels == class_idx
            class_features = support_features[class_mask]
            prototype = class_features.mean(dim=0)
            prototypes.append(prototype)
        
        prototypes = torch.stack(prototypes)
        
        # Calculate distances and logits
        distances = torch.cdist(query_features, prototypes)
        logits = -distances  # Negative distance as logits
        
        return logits
```

## Research Applications

This dataset is particularly well-suited for:

### Few-Shot Learning

- **Meta-learning algorithms** (MAML, Prototypical Networks, Relation Networks)
- **Metric learning approaches** (Siamese Networks, Triplet Networks)
- **Gradient-based meta-learning** methods

### Transfer Learning

- **Pre-training** on large-scale product data
- **Domain adaptation** from general images to products
- **Fine-tuning** strategies for product classification

### Computer Vision Research

- **Product recognition** and retrieval
- **E-commerce applications**
- **Retail automation**
- **Visual search** systems

## Benchmark Tasks

### Standard Few-Shot Learning Evaluation

The following benchmarks are recommended for evaluating few-shot learning models on this dataset:

#### Standard Evaluation Protocol

```python
import numpy as np
from sklearn.metrics import accuracy_score, classification_report
import json

def evaluate_fsl_model(model, dataset, num_episodes=600, n_way=5, k_shot=1, 
                       n_query=15, device='cuda'):
    """
    Evaluate few-shot learning model using standard protocol
    
    Returns:
        dict: Evaluation results with mean accuracy and confidence interval
    """
    model.eval()
    accuracies = []
    
    with torch.no_grad():
        for _ in tqdm(range(num_episodes), desc="Evaluating"):
            # Create episode
            support_data, query_data = dataset.create_episode_dataloader(
                n_way=n_way, k_shot=k_shot, n_query=n_query
            )
            
            support_images, support_labels = support_data
            query_images, query_labels = query_data
            
            # Move to device
            support_images = support_images.to(device)
            support_labels = support_labels.to(device)
            query_images = query_images.to(device)
            query_labels = query_labels.to(device)
            
            # Predict
            logits = model(support_images, support_labels, query_images)
            pred = logits.argmax(dim=1)
            
            # Calculate episode accuracy
            acc = (pred == query_labels).float().mean().item()
            accuracies.append(acc)
    
    # Calculate statistics
    mean_acc = np.mean(accuracies)
    std_acc = np.std(accuracies)
    ci_95 = 1.96 * std_acc / np.sqrt(len(accuracies))
    
    results = {
        'mean_accuracy': mean_acc,
        'std_accuracy': std_acc,
        'confidence_interval_95': ci_95,
        'num_episodes': num_episodes,
        'config': f"{n_way}-way {k_shot}-shot"
    }
    
    return results

# Benchmark configurations
benchmark_configs = [
    {'n_way': 5, 'k_shot': 1, 'n_query': 15},  # 5-way 1-shot
    {'n_way': 5, 'k_shot': 5, 'n_query': 15},  # 5-way 5-shot
    {'n_way': 10, 'k_shot': 1, 'n_query': 15}, # 10-way 1-shot
    {'n_way': 10, 'k_shot': 5, 'n_query': 15}, # 10-way 5-shot
]

# Run benchmarks
def run_benchmark_suite(model, dataset, num_episodes=600):
    """Run complete benchmark suite"""
    results = {}
    
    for config in benchmark_configs:
        config_name = f"{config['n_way']}-way_{config['k_shot']}-shot"
        print(f"\nEvaluating {config_name}...")
        
        result = evaluate_fsl_model(
            model, dataset, num_episodes=num_episodes, **config
        )
        results[config_name] = result
        
        print(f"Accuracy: {result['mean_accuracy']:.4f} ± {result['confidence_interval_95']:.4f}")
    
    return results

# Example usage
# results = run_benchmark_suite(model, test_dataset)
```

#### Cross-Domain Evaluation

```python
def create_cross_domain_split(dataset, train_ratio=0.6, val_ratio=0.2, test_ratio=0.2, seed=42):
    """
    Create train/validation/test splits at the class level for cross-domain evaluation
    
    Args:
        dataset: Hugging Face Dataset
        train_ratio: Proportion of classes for training
        val_ratio: Proportion of classes for validation  
        test_ratio: Proportion of classes for testing
        seed: Random seed
        
    Returns:
        dict: Splits with class indices for each set
    """
    np.random.seed(seed)
    
    # Get unique classes
    unique_classes = sorted(set(dataset['label']))
    n_classes = len(unique_classes)
    
    # Calculate split sizes
    n_train = int(n_classes * train_ratio)
    n_val = int(n_classes * val_ratio)
    n_test = n_classes - n_train - n_val
    
    # Shuffle and split classes
    shuffled_classes = np.random.permutation(unique_classes)
    train_classes = shuffled_classes[:n_train]
    val_classes = shuffled_classes[n_train:n_train + n_val]
    test_classes = shuffled_classes[n_train + n_val:]
    
    # Create sample indices for each split
    train_indices = [i for i, sample in enumerate(dataset) if sample['label'] in train_classes]
    val_indices = [i for i, sample in enumerate(dataset) if sample['label'] in val_classes]
    test_indices = [i for i, sample in enumerate(dataset) if sample['label'] in test_classes]
    
    return {
        'train': {'indices': train_indices, 'classes': train_classes.tolist()},
        'validation': {'indices': val_indices, 'classes': val_classes.tolist()}, 
        'test': {'indices': test_indices, 'classes': test_classes.tolist()}
    }

# Create cross-domain splits
splits = create_cross_domain_split(dataset)

print(f"Train classes: {len(splits['train']['classes'])}")
print(f"Validation classes: {len(splits['validation']['classes'])}")
print(f"Test classes: {len(splits['test']['classes'])}")
```

### Performance Baselines

Expected performance ranges for different few-shot learning approaches:

| Method | 5-way 1-shot | 5-way 5-shot | 10-way 1-shot | 10-way 5-shot |
|--------|--------------|--------------|----------------|----------------|
| Random Baseline | 20.0% | 20.0% | 10.0% | 10.0% |
| Nearest Neighbor | 35-45% | 55-65% | 25-35% | 45-55% |
| Prototypical Networks | 45-55% | 65-75% | 35-45% | 55-65% |
| MAML | 48-58% | 68-78% | 38-48% | 58-68% |
| Relation Networks | 50-60% | 70-80% | 40-50% | 60-70% |

### Utility Functions

```python
import os
import json
from pathlib import Path
import matplotlib.pyplot as plt
import seaborn as sns
from collections import Counter

def dataset_statistics(dataset):
    """
    Generate comprehensive statistics about the dataset
    
    Args:
        dataset: Hugging Face Dataset or list of samples
        
    Returns:
        dict: Dataset statistics
    """
    if hasattr(dataset, '__getitem__') and hasattr(dataset, '__len__'):
        # Hugging Face Dataset
        labels = dataset['label']
        class_names = dataset['class_name']
        image_ids = dataset['image_id']
    else:
        # List of samples
        labels = [sample['label'] for sample in dataset]
        class_names = [sample['class_name'] for sample in dataset]
        image_ids = [sample['image_id'] for sample in dataset]
    
    # Basic statistics
    n_samples = len(labels)
    n_classes = len(set(labels))
    class_counts = Counter(labels)
    
    # Calculate distribution statistics
    counts = list(class_counts.values())
    stats = {
        'total_samples': n_samples,
        'total_classes': n_classes,
        'avg_samples_per_class': n_samples / n_classes,
        'min_samples_per_class': min(counts),
        'max_samples_per_class': max(counts),
        'std_samples_per_class': np.std(counts),
        'class_distribution': dict(class_counts)
    }
    
    return stats

def plot_class_distribution(dataset, top_k=50, figsize=(15, 8)):
    """
    Plot class distribution
    
    Args:
        dataset: Dataset object
        top_k: Number of top classes to show
        figsize: Figure size
    """
    # Get class counts
    if hasattr(dataset, '__getitem__'):
        class_counts = Counter(dataset['label'])
    else:
        class_counts = Counter([sample['label'] for sample in dataset])
    
    # Get top k classes
    top_classes = class_counts.most_common(top_k)
    labels, counts = zip(*top_classes)
    
    # Plot
    plt.figure(figsize=figsize)
    bars = plt.bar(range(len(labels)), counts)
    plt.xlabel('Class ID')
    plt.ylabel('Number of Samples')
    plt.title(f'Class Distribution (Top {top_k} Classes)')
    plt.xticks(range(0, len(labels), max(1, len(labels)//10)), 
               [str(l) for l in labels[::max(1, len(labels)//10)]], rotation=45)
    
    # Add statistics text
    total_samples = sum(counts)
    avg_samples = total_samples / len(counts)
    plt.text(0.02, 0.98, f'Total Classes: {len(class_counts)}\n'
                         f'Shown Classes: {len(labels)}\n'
                         f'Avg Samples/Class: {avg_samples:.1f}',
             transform=plt.gca().transAxes, verticalalignment='top',
             bbox=dict(boxstyle='round', facecolor='wheat', alpha=0.5))
    
    plt.tight_layout()
    plt.show()
    
    return top_classes

def save_dataset_info(dataset, output_path="dataset_info.json"):
    """
    Save dataset information to JSON file
    
    Args:
        dataset: Dataset object
        output_path: Path to save the info file
    """
    stats = dataset_statistics(dataset)
    
    # Add additional metadata
    info = {
        'dataset_name': 'FSL Product Classification Dataset',
        'version': '1.0',
        'statistics': stats,
        'description': 'Few-shot learning dataset for product classification',
        'features': {
            'image': 'PIL Image object',
            'label': 'Class ID (int64)', 
            'class_name': 'Class name string',
            'image_id': 'Unique image identifier'
        }
    }
    
    # Save to file
    with open(output_path, 'w') as f:
        json.dump(info, f, indent=2)
    
    print(f"Dataset info saved to: {output_path}")
    return info

def verify_dataset_integrity(dataset_path="data.tzst"):
    """
    Verify dataset archive integrity
    
    Args:
        dataset_path: Path to the dataset archive
        
    Returns:
        bool: True if dataset is valid
    """
    from tzst import test_archive
    
    try:
        # Test archive integrity
        is_valid = test_archive(dataset_path)
        
        if is_valid:
            print(f"✅ Dataset archive '{dataset_path}' is valid")
            
            # Get archive info
            from tzst import list_archive
            contents = list_archive(dataset_path, verbose=True)
            
            print(f"📁 Archive contains {len(contents)} files")
            
            # Check for expected structure
            class_dirs = [item['name'] for item in contents 
                         if item['name'].startswith('class_') and item['name'].endswith('/')]
            print(f"🏷️  Found {len(class_dirs)} class directories")
            
            return True
        else:
            print(f"❌ Dataset archive '{dataset_path}' is corrupted")
            return False
            
    except Exception as e:
        print(f"❌ Error verifying dataset: {e}")
        return False

def create_data_splits(dataset, split_ratios={'train': 0.8, 'test': 0.2}, 
                      strategy='random', seed=42):
    """
    Create train/test splits from the dataset
    
    Args:
        dataset: Dataset object
        split_ratios: Dictionary with split names and ratios
        strategy: 'random' or 'stratified'
        seed: Random seed
        
    Returns:
        dict: Split datasets
    """
    from sklearn.model_selection import train_test_split
    
    np.random.seed(seed)
    
    if strategy == 'random':
        # Simple random split
        indices = list(range(len(dataset)))
        train_size = split_ratios.get('train', 0.8)
        
        train_indices, test_indices = train_test_split(
            indices, train_size=train_size, random_state=seed
        )
        
        splits = {
            'train': dataset.select(train_indices),
            'test': dataset.select(test_indices)
        }
        
    elif strategy == 'stratified':
        # Stratified split maintaining class distribution
        labels = dataset['label']
        indices = list(range(len(dataset)))
        train_size = split_ratios.get('train', 0.8)
        
        train_indices, test_indices = train_test_split(
            indices, train_size=train_size, stratify=labels, random_state=seed
        )
        
        splits = {
            'train': dataset.select(train_indices),
            'test': dataset.select(test_indices)
        }
    
    # Print split information
    for split_name, split_dataset in splits.items():
        n_samples = len(split_dataset)
        n_classes = len(set(split_dataset['label']))
        print(f"{split_name.capitalize()} split: {n_samples} samples, {n_classes} classes")
    
    return splits
```

## Troubleshooting

### Common Issues and Solutions

#### 1. Archive Extraction Issues

**Problem**: Error extracting `data.tzst` file

```text
TzstDecompressionError: Failed to decompress archive
```

**Solution**:

```python
# Verify archive integrity first
from tzst import test_archive
if not test_archive("data.tzst"):
    print("Archive is corrupted. Please re-download.")

# Use streaming mode for large archives
from tzst import extract_archive
extract_archive("data.tzst", "output/", streaming=True)
```

#### 2. Non-continuous Class Labels

**Problem**: Class labels are not continuous (0, 1, 2, ...)

**Solution**:

```python
# Create label mapping
unique_labels = sorted(set(dataset['label']))
label_to_idx = {label: idx for idx, label in enumerate(unique_labels)}

# Apply mapping
def map_labels(example):
    example['mapped_label'] = label_to_idx[example['label']]
    return example

dataset = dataset.map(map_labels)
```

#### 3. CUDA/GPU Issues

**Problem**: CUDA out of memory during training

**Solution**:

```python
# Reduce batch size or use CPU
device = torch.device('cpu')  # Force CPU usage

# Or use gradient accumulation
accumulation_steps = 4
for i, (support_data, query_data) in enumerate(dataloader):
    loss = model(support_data, query_data) / accumulation_steps
    loss.backward()
    
    if (i + 1) % accumulation_steps == 0:
        optimizer.step()
        optimizer.zero_grad()
```

### Performance Tips

1. **Use appropriate image sizes**: For few-shot learning, 84x84 or 224x224 are common choices
2. **Enable streaming mode**: For memory-efficient processing of large archives
3. **Use data augmentation**: Improve few-shot performance with transforms
4. **Cache preprocessed data**: Save processed episodes to disk for faster iteration

## Citation

If you use this dataset in your research, please cite it as shown on the Hugging Face dataset page:

<https://huggingface.co/datasets/xixu-me/fsl-product-classification?doi=true>

## License

This dataset is released under the MIT License. See the [LICENSE file](LICENSE) for details.

## Data Ethics and Responsible Use

This dataset is intended for academic research and educational purposes in few-shot learning and computer vision. Users should:

- **Respect intellectual property**: Images may be subject to copyright; use only for research purposes
- **Consider bias**: Be aware that product categories may reflect certain demographic or geographic biases
- **Commercial use**: While the license permits it, consider the ethical implications of commercial applications
- **Attribution**: Please cite this dataset in any published work

## Limitations

- **Image quality**: Variable image quality and backgrounds may affect model performance
- **Class imbalance**: Some classes may have significantly fewer images than others
- **Non-continuous labels**: Class numbers are not sequential, which may require label mapping
- **Temporal bias**: Product images reflect trends from the time of collection